try
Dim da As String = "+100acs+"

            Dim con As SqlConnection = New SqlConnection("Data Source=RAHUL-034890AF0\SERVER2005;Initial Catalog=user_accounts; Integrated Security =True")

            Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into sales_details (bill_number,product_id,quantity,rate,amount) VALUES ('" + da + " ','" + Ddpproducts.SelectedItem.ToString + " ','" + Textquant.Text + "','" + Ddpproducts.SelectedValue + "','" + 2306 + "')", con)

 

            command.BeginExecuteNonQuery()

 

            con.Close()

 

        Catch [x] As Exception

 

            Txterror.text = x

 

 

 

       

End Try

I get the following error in my error textbox:

System.InvalidCastException: Conversion from string "Insert into sales_details (bill_" to type 'Double' is not valid. ---> System.FormatException: Input string was not in a correct format. at Microsoft.VisualBasic.CompilerServices.Conversions.ParseDouble(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value, NumberFormatInfo NumberFormat) --- End of inner exception stack trace --- at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value) at _Default.btnadd_Click(Object sender, EventArgs e) in D:\sms_new\salesbill.aspx.vb:line 71

My bill number field is nvarchar(10) in sql2005 and even if I replace da with numbers or alphabets (eg– 123, abc)I still get and error.

try
Dim da As String = "+100acs+"

            Dim con As SqlConnection = New SqlConnection("Data Source=RAHUL-034890AF0\SERVER2005;Initial Catalog=user_accounts; Integrated Security =True")

            Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into sales_details (bill_number,product_id,quantity,rate,amount) VALUES ('" + da + " ','" + Ddpproducts.SelectedItem.ToString + " ','" + Textquant.Text + "','" + Ddpproducts.SelectedValue + "','" + 2306 + "')", con)

 

            command.BeginExecuteNonQuery()

 

            con.Close()

 

        Catch [x] As Exception

 

            Txterror.text = x

 

 

 

       

End Try

I get the following error in my error textbox:

System.InvalidCastException: Conversion from string "Insert into sales_details (bill_" to type 'Double' is not valid. ---> System.FormatException: Input string was not in a correct format. at Microsoft.VisualBasic.CompilerServices.Conversions.ParseDouble(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value, NumberFormatInfo NumberFormat) --- End of inner exception stack trace --- at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(String Value) at _Default.btnadd_Click(Object sender, EventArgs e) in D:\sms_new\salesbill.aspx.vb:line 71

My bill number field is nvarchar(10) in sql2005 and even if I replace da with numbers or alphabets (eg– 123, abc)I still get and error.

I think the error is not because of da or your bill_number column. I am not sure but it may be because of rate or amount you are inserting. what "2306" in your insert statement ? what the data type of quantity, rate and amount in your table ?

As per the stack trace it says problem with bill number...
I am using money for rate, amount & integer for quantity..
Besides i have put validators on the page to ensure only integer values are excepted...
2306 is a random value i was trying to insert in the table to test my connection

If I'm not wrong then I think You've missed the con.open();

Hope this helps........

As per the stack trace it says problem with bill number...
I am using money for rate, amount & integer for quantity..
Besides i have put validators on the page to ensure only integer values are excepted...
2306 is a random value i was trying to insert in the table to test my connection

no dude- the problem is not with "da", i have checked in sample application. what the data type of Product_id in sql table ?

Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into sales_details (bill_number,product_id,quantity, rate, amount, customer_name,customer_address) VALUES ('" + Label13.Text + "','" + Ddpproducts.SelectedItem.ToString + "','" + Textquant.Text + "','" + Ddpproducts.SelectedValue + "','" + (Textquant.Text * Ddpproducts.SelectedValue).ToString + "','" + Txtname.Text + "','" + Txtaddr.Text + "')", con)

Just to refresh, consider the above code for a sales bill page.
I have used money datatype for rate & amount, nvarchar for product_id & bill_number and integer for quantity.

If it makes things any better to solve, in another page add customer i used the following queries:

'Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into customers (membership_id,name,membership_date,membership_type,dob,gender,address,mobile,telephone1,telephone2,discountdeals,seasonsales,newarrivals,specialoffers)values('" + Textmemid.Text + "', '" + Textnam.Text + "','" + BasicDatePicker1.SelectedDate + "','" + ddtype.SelectedValue + "','" + BasicDatePicker2.SelectedDate + "','" + RadioButton3.Checked + "','" + Txtadd.Text + "'.'" + Txtmob.Text + "','" + Texttel.Text + "','" + Textoff.Text + "', '" + Checkdd.Checked + "','" + Checkss.Checked + "','" + Checkna.Checked + "','" + Checkso.Checked + "'  ) ", con)
        Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into customers (membership_id,name,membership_type,address)VALUES ('" + Textmemid.Text + "', '" + Textnam.Text + "','" + ddtype.SelectedValue + "','" + Txtadd.Text + "')", con)

While the shorter query works fine, it gives me error in the first one. It gives error wheneva i try to insert details of a checkbox or gender or type.
MY datatypes here are: nvarchar for customerid, employeeid & bit for the checkboxes and gender
& numeric for telephone numbers & datetime for dob, membership_date.

Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into sales_details (bill_number,product_id,quantity, rate, amount, customer_name,customer_address) VALUES ('" + Label13.Text + "','" + Ddpproducts.SelectedItem.ToString + "','" + Textquant.Text + "','" + Ddpproducts.SelectedValue + "','" + (Textquant.Text * Ddpproducts.SelectedValue).ToString + "','" + Txtname.Text + "','" + Txtaddr.Text + "')", con)

Just to refresh, consider the above code for a sales bill page.
I have used money datatype for rate & amount, nvarchar for product_id & bill_number and integer for quantity.

If it makes things any better to solve, in another page add customer i used the following queries:

'Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into customers (membership_id,name,membership_date,membership_type,dob,gender,address,mobile,telephone1,telephone2,discountdeals,seasonsales,newarrivals,specialoffers)values('" + Textmemid.Text + "', '" + Textnam.Text + "','" + BasicDatePicker1.SelectedDate + "','" + ddtype.SelectedValue + "','" + BasicDatePicker2.SelectedDate + "','" + RadioButton3.Checked + "','" + Txtadd.Text + "'.'" + Txtmob.Text + "','" + Texttel.Text + "','" + Textoff.Text + "', '" + Checkdd.Checked + "','" + Checkss.Checked + "','" + Checkna.Checked + "','" + Checkso.Checked + "'  ) ", con)
        Dim command As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand("Insert into customers (membership_id,name,membership_type,address)VALUES ('" + Textmemid.Text + "', '" + Textnam.Text + "','" + ddtype.SelectedValue + "','" + Txtadd.Text + "')", con)

While the shorter query works fine, it gives me error in the first one. It gives error wheneva i try to insert details of a checkbox or gender or type.
MY datatypes here are: nvarchar for customerid, employeeid & bit for the checkboxes and gender
& numeric for telephone numbers & datetime for dob, membership_date.

Okay. try to convert the value of check boxes to 1 or 0 by using Convert.ToInt16. because the reason is bit data type in sql holds 1/0 for true/false.
when you are using say Checkdd.Checked, it holds true/ false not 1/0. so your code looks like
Convert.ToInt16(Checkdd.Checked) and it will work for you.

thanx! would try and mark it as answer if it works.

It should work.

thanx! would try and mark it as answer if it works.

It should work.

is it work ?