Assigning Value

[toko]

Okay, im trying to write a simple calculator. Heres my code:

Public Class Form1
    Dim value1 As Double
    Dim value2 As Double
    Dim sign As String

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text = " " Then TextBox1.Text = "1" Else 
        TextBox1.Text = TextBox1.Text & "1"
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        value1 = textbox1.text
        If TextBox1.Text = " " Then TextBox1.Text = "2" Else 
        TextBox1.Text = TextBox1.Text & "2"
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If TextBox1.Text = " " Then TextBox1.Text = "+" Else 
        TextBox1.Text = TextBox1.Text & "+"
    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged

    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        value2= textbox1.Text        
        If sign = "-" Then TextBox1.Text = value1 - value2 Else 
        If sign = "+" Then TextBox1.Text = value1 + value2 Else 
        If sign = "*" Then TextBox1.Text = value1 * value2 Else 
        If sign = "/" Then TextBox1.Text = value1 / value2
        If TextBox1.Text = " " Then TextBox1.Text = "=" Else 
        TextBox1.Text = TextBox1.Text & "="
    End Sub
End Class

the problem i have is that the "value1= textbox1.Text" and "value2= textbox1.Text" don't work.

any help would be appreciated =)

[Jx_Man]

it cause if textbox1 or textbox2 empty and it's empty string. value1 and value2 is double, so you cannot assign value directly.
you can change your assignment with this code :

value1 = Val(TextBox1.Text)

[toko]

k this is my new script:

Public Class Form1
    Dim value1 As Double
    Dim value2 As Double
    Dim sign As String

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text = " " Then
            TextBox1.Text = Button1.Text
        Else
            TextBox1.Text = TextBox1.Text & Button1.Text
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click 
        If TextBox1.Text = " " Then
            TextBox1.Text = Button2.Text
        Else
            TextBox1.Text = TextBox1.Text & Button2.Text
        End If
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        value1 = TextBox1.Text
        If TextBox1.Text = " " Then
            TextBox1.Text = "+"
        Else
            TextBox1.Text = TextBox1.Text & "+"
        End If
        sign = Button3.Text
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        value2 = TextBox1.Text
        Select Case sign
            Case "-"
                TextBox1.Text = value1 - value2
            Case "+"
                TextBox1.Text = value1 + value2
            Case "*"
                TextBox1.Text = value1 * value2
            Case "/"
                TextBox1.Text = value1 / value2
        End Select
    End Sub
End Class

but when i press "equal" the program crashes =(

plz help