Javascript to submit form when you hit Enter

you will have to change the img tag to do that.

<img src="<ur imgsrc >" onClick="document.forms[0].submit()" />

PS : The assumption is that tyou only have one form in this HTML page

instead of using an <img src="whatever.jpg"/> tag have you considered using
<input type="image" src="whatever.jpg"/>

The image has some rollover effects applied to it.  I'm perfectly content to use an <input src=""> tag if the effects can be maintained.  I avoid javascript in my design and development, so I'll post what the designer added for the rollover.


 <script type="text/JavaScript">
<!--
function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->
    </script>


and this for the button.


<a href="javascript:document.loginform.submit();"><img src="images/home_button_login.gif" width="129" height="19" border="0" id="Image1" onMouseOver="MM_swapImage('Image1','','images/home_button_login_hover.gif',1)" onMouseOut="MM_swapImgRestore()"></a>