function ValidateFirstName(source, args)

    {
        var fn = document.getElementById("ctl00_LabelContentArea_firstname");        

        args.IsValid = true;
        if (fn.value.trim().length == "0")
            {
                args.IsValid = false;
            }
          
    }
    
function ValidateLastName(source, args)

    {
        var ln = document.getElementById("ctl00_LabelContentArea_lastname");

        args.IsValid = true;
        if (ln.value.trim().length == "0")
            {
                args.IsValid = false;
            }
          
    }
    
function ValidatePassword(source, args)

    {
        var pwd = document.getElementById("ctl00_LabelContentArea_TBPassword");

        args.IsValid = true;
        if (pwd.value.trim().length == "0")
            {
                args.IsValid = false;
            }
          
    }
    
String.prototype.trim = function () {
    return this.replace(/^\s+|\s+$/g, "");
};   

/*
<asp:RegularExpressionValidator ID="validEmail" runat="server" ErrorMessage="Email Address Is Invalid" Text="*" ControlToValidate="email"
ValidationExpression=".*@.*\..*"></asp:RegularExpressionValidator> */