Firefox says: document.getElementById.bgtd is undefined

Hi all,

I have an .asp page on which you can change the background picture of a cell by simply selecting the desired color from a dropdown field.

When running the page in Firefox its Error console tells me the following:

Error: document.getElementById.bgtd is undefined
Source File: [localhost…]
Line: 29

Here is the code:

<select name=ADDITIONALINFO1 ID=“Select1” onchange=“changebg(document.forms[0].ADDITIONALINFO1[document.forms[0].ADDITIONALINFO1.selectedIndex].value)”>
<option value=“White”> White
<option value=“Black”> Black
<option value=“Blue”> Blue
</select>

And here is the changebg script:

function changebg(color){
if (color==“Black”)
document.getElementById(“bgtd”).background = “img/bg-tshirt5.jpg”;
else if (color==“Blue”)
document.getElementById(“bgtd”).background = “img/bg-tshirt_bl.jpg”;
else
document.getElementById(“bgtd”).background = “img/bg-tshirt2.jpg”;

document.forms[0].bgimg.value = document.getElementById(“bgtd”).background;
}

Here is the table where the image is displayed as bachground:

<td width=“353” background=“img/bg-tshirt2.jpg” height=“269” id=“bgtd”>
<p align=“center”><font size=“1”>      <br>
   
<img src=“<%=imgSrc%>”></font></td>

Internet Explorer does not complain and does the job without any errors.
I Could not find out how to make it work also with Firefox.

Any comments are appreciated.

document.getElementById(“bgtd”).background

should be

document.getElementById(“bgtd”).style.backgroundImage