or die mysql_error()

//clear the various boxes
lstNetAdd.Items.Clear();
txtCIDR.Text = "";
txtSubNetShown.Text = "";
txtBitsBorrow.Text = "";
 
//pull the value into the variable
double dblSubnetsNeeded, dblBitsToBorrow, dblNET4; 
dblSubnetsNeeded = Double.Parse(txtSubnetsNeeded.Text); 
//if they only need one subnet what to do
if (dblSubnetsNeeded <= 1 || dblSubnetsNeeded >= 256)
{
	//Value to high or too low
	MessageBox.Show("Please Enter a Value Betweeen 2 and 255", "Error: Value Range", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
//what to do if they want more than one
else
{
	//determin number of bits to borrow
	dblBitsToBorrow = Math.Log(dblSubnetsNeeded)/Math.Log(2);
	//Declare Variables to Handle left over bits
	decimal decBitsToBorrow = Convert.ToDecimal(dblBitsToBorrow),
	 decBitsLeftOver;
	//Mod out the decimal
	decBitsLeftOver = (decBitsToBorrow % 1);
 
	//if there are decimal places
	if (decBitsLeftOver > 0)
	{
	 //remove the decimal places, incriment the bits by one and then convert for display
	 decBitsToBorrow = decBitsToBorrow - decBitsLeftOver;
	 decBitsToBorrow += 1; 
	 Convert.ToString(decBitsToBorrow);
	}//endif
 
	//display the bits to borrow
	txtBitsBorrow.Text = String.Format( "{0:0}", decBitsToBorrow);
	//display the current subnet
	dblBitsToBorrow = Convert.ToDouble(decBitsToBorrow);
	//determin the subnet
	dblNET4 = 256 - ((Math.Pow(2, 8)) - (Math.Pow (2, (8-dblBitsToBorrow))));
	/* the following section will display the first few results of the subnet addy */
	//variables for the first subnet, counter and highest subnet
	double dblFirstNET4 = dblNET4 - dblNET4,
	 dblNETStore = dblNET4,
	 dblHighestSubnet = 255 - dblNET4;
	//display first and second subnets
	lstNetAdd.Items.Add( "192.168.1." + dblFirstNET4);
	lstNetAdd.Items.Add( "192.168.1." + dblNET4); 
	/*end pre-address display*/
	/*Now itterate through the last of the subnets*/
	//only work untill we are are less than highest subnet
	while (dblNET4 < dblHighestSubnet ) 
	{
	 //increment the subnet by one and display the subnet
	 dblNET4 = dblNET4 + dblNETStore;
	 lstNetAdd.Items.Add( "192.168.1." + dblNET4);
	}
	/*end itteration*/
	/*Show CIDR notation and #of Subnets*/
	decimal decCIDR = 24 + decBitsToBorrow; 
	txtCIDR.Text += "/";
	txtCIDR.Text += String.Format( "{0:0}", decCIDR);
	txtSubNetShown.Text = Convert.ToString(lstNetAdd.Items.Count);
	/*end CIDR and subnets*/
}//endif

dblSubnetsNeeded = Double.Parse(txtSubnetsNeeded.Text);

 
string inputString;
 
try 
{
     Convert.ToInt32(inputString);
}
catch (System.FormatException)
{
     Console.Writeline("Please input a number in inputString");
}

 private static void IsNumeric(string input)
        {
            try
            {
                Convert.ToInt32(input);
            }
            catch (Exception error)
            {
                MessageBox.Show(error.Message);
            }
        }

   IsNumeric("4");

   IsNumeric("F");

private  bool IsNumeric(string input)
        {
bool isNum = true;
            try
            {
                int.Parse(input);
            }
            catch
            {
               isNum = false;
            }
 
return isNum;
        }

		static bool IsaNumber(string num)
		{
			double dbl;
			return double.TryParse(num, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.CurrentCulture, out dbl);
 
		}

try  // check if number is a decimal
                {
                  string i;
 
                    decValue  =
 checked((uint)System.Convert.ToUInt32(numberinput.Text));
                }
                    catch (System.Exception i)
                        {
 
                            MessageBox.Show("input a decimal");
                            return;
                        }