How to disable backspace in textbox using JavaScript in ASP.NET

In this article I will explain How to disable backspace except textbox using JavaScript in ASP.NET.

(Or)

How to disable backspace in textbox using JavaScript in ASP.NET

I designed the ASPX page. In that page I declared one textbox, Textbox not allowed backspace.

Below is sample code for textbox design. Here we can use onKeyDown event for disable back button code.

<asp:TextBox runat="server" ID="txtPODate" Width="200px"

                                        onKeyDown="preventBackspace();"></asp:TextBox>

Below is the sample JavaScript code for disable Back Button.

function preventBackspace(e) {

            var evt = e || window.event;

            if (evt) {

                var keyCode = evt.charCode || evt.keyCode;

                if (keyCode === 8) {

                    if (evt.preventDefault) {

                        evt.preventDefault();

                    } else {

                        evt.returnValue = false;

                    }

                }

            }

        }