Question

I use this code for decimal validation.It was working fine.but it allow to enter the alphabets into the text box. when i exit from the text box then only the error message will show nearby textbox.I need,if i press the alphabets the text box doesn’t allow to enter the text box , how to do this?

<asp:RegularExpressionValidator ControlToValidate="txtNumber" 
                    runat="server" ValidationExpression="^[1-9]\d*(\.\d+)?$"
                        ErrorMessage="Please enter only numbers">
                    </asp:RegularExpressionValidator>

Answer 1

Using Javascript:

<asp:TextBox ID="TextBox2" onkeypress="AllowOnlyNumeric(event);" 
   runat="server"></asp:TextBox>

Javascript Code:

function AllowOnlyNumeric(e) {
    if (window.event) // IE 
    {
        if (((e.keyCode < 48 || e.keyCode > 57) & e.keyCode != 8) & e.keyCode != 46) {
            event.returnValue = false;
            return false;

        }
    }
    else { // Fire Fox
        if (((e.which < 48 || e.which > 57) & e.which != 8) & e.which != 46) {
            e.preventDefault();
            return false;

        }
    }
}