i tried what you just told me and it does not appear the image at all.
If they are server side images, you can reference them like this:
This only works with server side paths as the ~ is an ASP.NET thing.
In your case, try referencing the root, assuming Pics is in the root:
<table cellspacing="0" style="background-repeat: no-repeat; width: 901px; height: 493px; background-image: url('/Pics/Main_Backroung.jpg');">
Note the / before the folder Pics.
Alternatively, move the CSS to a separate CSS file. If you store it in a folder at the same level as Pics (like /Css), you can refer to the images like this:
You then need to set a class on the table like this:
<table cellspacing="0" class="MyTable">
By moving the CSS to a separate file, it's easy to refer to images from that file, as the images are searched for relative to the .CSS file; not relative to the ASPX file (or Master Page) that uses them.