Validate the Maximum no. of Characters allowed in TextBox Using Java Script.

Function for Check and limit the number of characters allowed in a Textbox.

CheckLength(txt,5) : It will allow only 5 Characters in text box.

Javascript :

    function CheckLength(obj,Length)
    {
        if (obj.value.length>Length)
        {
            alert("Exceeding Maximum " + Length +" Characters")
            obj.focus()
            obj.select()
        }
    } 

aspx :

asp:textbox id="TextBox1" onkeyup="CheckLength(this,5)" runat="server" width="238px"