Image in master page not showing on some pages in ASP.Net

<div class="header">
<table>
<tr>
             <td colspan="3">
             <img src="Images/placement_web_panner.jpg"  
                     style="height: 153px; width: 1009px; margin-top: 0px;"/>
             </td>
             </tr>
</table>
</div>

The above code contains an image tag in header of the master page..

whenever I open a new web form linked with this master page.. the existing image doesn't open or isn't displayed..

what can I do for this problem??..

and one more ques...

the overall contents of the web pages are moving beyond their original locations after being run the program..

whereas the contents are in their own locations before execution..

how can I make them static to view??