Hi arsh.whd,
Check this example. Now please take its reference and correct your code.
HTML
<asp:TextBox runat="server" ID="txtCharacters" />
<asp:Button Text="Get Supplier Id" runat="server" OnClick="Generate" />
<br />
<asp:Label ID="lblSupplierId" runat="server" />
C#
protected void Generate(object sender, EventArgs e)
{
int value = 1;
string code = txtCharacters.Text.Trim();
string supplierId = "";
if (code.Length == 3)
{
supplierId = code + value.ToString().PadLeft(2, '0');
}
else if (code.Length == 4)
{
supplierId = code + value.ToString().PadLeft(1, '0');
}
lblSupplierId.Text = supplierId;
}
VB.Net
Protected Sub Generate(ByVal sender As Object, ByVal e As EventArgs)
Dim value As Integer = 1
Dim code As String = txtCharacters.Text.Trim()
Dim supplierId As String = ""
If code.Length = 3 Then
supplierId = code & value.ToString().PadLeft(2, "0"c)
ElseIf code.Length = 4 Then
supplierId = code & value.ToString().PadLeft(1, "0"c)
End If
lblSupplierId.Text = supplierId
End Sub
Screenshot