Validating a text box

[manil]

hi! i want to make validation on a text box so that the first character is only A, B, C, or X..

sCustomerAccountNumber = txtCustomerAccountNumber.text

If sCustomerAccountNumber.Chars(0) <> Chr(65) Then
            sErrorMessage = sErrorMessage & "Customer Account Number should start with a letter!" & vbCrLf & "e.g. A, B, C or X" & vbCrLf & "e.g. A1234567" & vbCrLf
            bErrorOccurred = True
        ElseIf sCustomerAccountNumber.Chars(0) <> Chr(66) Then
            sErrorMessage = sErrorMessage & "Customer Account Number should start with a letter!" & vbCrLf & "e.g. A, B, C or X" & vbCrLf & "e.g. A1234567" & vbCrLf
            bErrorOccurred = True
        ElseIf sCustomerAccountNumber.Chars(0) <> Chr(67) Then
            sErrorMessage = sErrorMessage & "Customer Account Number should start with a letter!" & vbCrLf & "e.g. A, B, C or X" & vbCrLf & "e.g. A1234567" & vbCrLf
            bErrorOccurred = True
        ElseIf sCustomerAccountNumber.Chars(0) <> Chr(88) Then
            sErrorMessage = sErrorMessage & "Customer Account Number should start with a letter!" & vbCrLf & "e.g. A, B, C or X" & vbCrLf & "e.g. A1234567" & vbCrLf
            bErrorOccurred = True
End If

what happens with these code is whenever i try to put in A, B, C, or X.. i get the error message.. should i convert this into a loop..??

[manil]

can someone close this..?? already found out how to do it..

[dglienna]

Click on Thread Tools, and then Mark as RESOLVED. Only you can close it out.

Also, it'd help the next person to post the answer to any question.

Thanks

[Shuja Ali]

You should also look at Regular Expressions. You will have to write less code and it will be easier to maintain and understand.

[manil]

what's Regular Expressions..??

this is what i did:

sChar1 = Mid(txtCustomerAccountNumber.text, 1, 1)

If sChar1 <> "A" And sChar1 <> "B" And sChar1 <> "C" And sChar1 <> "X" Then
            sErrorMessage = sErrorMessage & "Customer Acount Number should start with A, B, C, or X" & vbCrLf & "e.g. A, B, C or X" & vbCrLf & "e.g. A1234567" & vbCrLf
            bErrorOccurred = True

but it didn't work properly... any suggestions..??

[Alsvha]

Use a regular expression such as Shuja Ali suggests to make the validation logic.

You can take a look at it here:
http://msdn.microsoft.com/en-us/library/hs600312.aspx

It is a powerful tool and well worth the time to get introduced to.

[WillAtwell]

Normally I just use an instr statement for such checks.

Dim ValidChars as String="ABCX"
 
if instr(ValidChars,Mid(txtCustomerAccountNumber.text, 1, 1))=0 then
 
' do error stuff here
end if

[Marraco]

hi! i want to make validation on a text box so that the first character is only A, B, C, or X..
...

		Select Case sCustomerAccountNumber.Chars(0)
			Case "A", "B", "C", "X"
				'Is ok
			Case Else
				'Is Wrong
				sErrorMessage &= "Customer Account Number should start with a letter!" & vbCrLf & _
								 "e.g. A, B, C or X" & vbCrLf & _
								 "e.g. A1234567" & vbCrLf
				bErrorOccurred = True
		End Select

[HairyMonkeyMan]

How about a custom user control that takes a regular expression as a property and an isvalid property that gets set when valid - you could include an error provider in the control.