I have been looking online for a Watermark effect for my textboxes to get some help and found a piece of code which looks like the following :

Javascript:

function WaterMark(objtxt, event) {

var defaultText = Username;

var defaultpwdText = Password;

// Condition to check textbox length and event type

if (objtxt.id == tb_Username || objtxt.id == tb_Password) {

    if (objtxt.value.length == 0 & event.type == blur) {

        //if condition true then setting text color and default text in textbox

        if (objtxt.id == tb_Username) {

            objtxt.style.color = Gray;

            objtxt.value = defaultText;

        }

        if (objtxt.id == tb_Password) {

            document.getElementById(<%= tb_TempPassword.ClientID %>).style.display = block;

            objtxt.style.display = none;

        }

    }

}

// Condition to check textbox value and event type

if ((objtxt.value == defaultText || objtxt.value == defaultpwdText) & event.type == focus) {

    if (objtxt.id == tb_Username) {

        objtxt.style.color = black;

        objtxt.value = ;

    }

    if (objtxt.id == tb_TempPassword) {

        objtxt.style.display = none;

        document.getElementById(<%= tb_Password.ClientID %>).style.display = ;

        document.getElementById(<%= tb_Password.ClientID %>).focus();

    }

}

}

Then the HTML:

<asp:TextBox runat=server ID=tb_Username Text=Username onblur=WaterMark(this, event); onfocus=WaterMark(this, event); />



<asp:TextBox runat=server ID=tb_TempPassword Text=Password onfocus=WaterMark(this, event); ForeColor=Gray />



<asp:TextBox runat=server ID=tb_Password TextMode=Password text=Password Style=display:none onblur=WaterMark(this, event);/>

But for some reason when i run my code the Username box works fine but the password box comes up with an error saying:

0x800a138f - JavaScript runtime error: Unable to get property 'style' of undefined or null reference

I have been looking online for a fix and nothing is working?
Is this because my Textbox is linking to a CSS stylesheet?

Any help would be greatly appreciated.