image zoom and scrollbar

[neo007]

Hi,
I'm working on modifying Discuz forum code to fit my purposes. One major change is about image zoom. The original setting is that when an image is wider than screenwidth*0.7, it will be automatically zoomed to *0.7. I want to disable zoom function, display images with original size.
Here is the code to display image attachment:

PHP: Select all

<!--{if !$attach['price'] || $attach['payed']}-->
 <!--{if $attach['thumb']}-->
  <!--{if ($attachrefcheck || $attach['remote']) && !($attach['remote'] && substr($ftp['attachurl'], 0, 3) == 'ftp' && !$ftp['hideurl'])}-->
   <a href="attachment.php?aid=$attach[aid]&amp;noupdate=yes&amp;nothumb=yes" target="_blank"><img src="attachment.php?aid=$attach[aid]" border="0" alt="{lang image_thumb}" /></a>
  <!--{else}-->
   <a href="$attach[url]/$attach[attachment]" target="_blank"><img src="$attach[url]/$attach[attachment].thumb.jpg" border="0" alt="{lang image_thumb}" /></a>
  <!--{/if}-->
 <!--{else}-->
  <!--{if ($attachrefcheck || $attach['remote']) && !($attach['remote'] && substr($ftp['attachurl'], 0, 3) == 'ftp' && !$ftp['hideurl'])}-->
   <img src="attachment.php?aid=$attach[aid]&amp;noupdate=yes" border="0" onload="attachimg(this, 'load', '{lang image_open_zoom}')" onmouseover="attachimg(this, 'mouseover')" onclick="attachimg(this, 'click', 'attachment.php?aid=$attach[aid]')" onmousewheel="return imgzoom(this)" alt="" />
  <!--{else}-->
   <img src="$attach[url]/$attach[attachment]" border="0" onload="attachimg(this, 'load', '{lang image_open_zoom}')" onmouseover="attachimg(this, 'mouseover')" onclick="attachimg(this, 'click', '$attach[url]/$attach[attachment]')" onmousewheel="return imgzoom(this)" alt="" />
  <!--{/if}-->
 <!--{/if}-->
<!--{/if}--> 

And here is the related javascript code about zoom, in "common.js":

PHP: Select all

function attachimg(obj, action, text) {
 if(action == 'load') {
  if(obj.width > screen.width * 0.7) {
   obj.resized = true;
   obj.width = screen.width * 0.7;
   obj.alt = text;
  }
  obj.onload = null;
 } else if(action == 'mouseover') {
  if(obj.resized) {
   obj.style.cursor = 'hand';
  }
 } else if(action == 'click') {
  if(!obj.resized) {
   return false;
  } else {
   window.open(text);
  }
 }
} 

I have tried to changed

PHP: Select all

 if(obj.width > screen.width * 0.7) 

into

PHP: Select all

 if(obj.width > screen.width * 3) 

After that, large images don't zoom any more, but I still want more:
1, since image is wider than screen, there should be a horizontal scrollbar in browser window. But it never happens.
2, when there comes such a large LINKED image (with vB code [img]) ----not attachment image---- if "mouseover", the image will be zoomed..... (attachment image is ok). How to fix this?
All in all, I want to achieve: all wide pictures do not zoom. And a horizontal scrollbar shows to fit the widest picture.
I'm new to javascript. Just read some basics, and can not find out what's wrong. So please help with this .
Thanks.