Two search box return key conflict

[nizamo]

This happens only in Internet Explorer. I have two input search boxes one is Google site search and other is the other box wikipedia.

If I put some text on search box "Sitede Ara" (Google site search) and hit return key then two window opens (Google & Wikipedia, how to resolve this conflict. I know it's because Wikipedia scripts' key event litener but if I remove it then return key won't work for Wikipedia box. I prefered this Wikipedia script because unicode chars like ş,ğ can pass through it.

Example page:
http://www.aymavisi.org/hikaye/Dostu...%20Cibran.html


Google site search code:

<form id="searchbox_007319955694884483973:pnnwgtpio7g0" action="http://www.google.com/search" style="line-height: 100%; font-size:10pt; font-family:Times New Roman; background-color:#444577
; text-align:center" target="_blank">
			<font size="3" face="Tahoma">
			<input type="hidden" name="cof0" value="FORID:0" />
			<input type="hidden" name="cx0" value="007319955694884483973:pnnwgtpio7g" />

			</font>

			<div style="padding-top: 2px">

			<font size="3">

			<input name="q" size="16" value=" " style="font-family:Tahoma; text-align:center; vertical-align:middle" /></font><span style="font-size: 7pt"><font size="3"><input type="submit" name="sa" value="Sitede Ara" style="font-family:Tahoma; width:75; height:18; vertical-align:middle" /></font></span></div>
			</p>
			<font size="3" face="Tahoma">
			<input type="hidden" name="cx" value="007319955694884483973:pnnwgtpio7g" />
			<input type="hidden" name="cof" value="FORID:0" />
			</font>
		</form>

----------------------------------------------------------------


Wikipedia script code:

<script language="JavaScript" type="text/javascript">
document.onkeydown = function(ev) {	
    var key;
    ev = ev || event;
    key = ev.keyCode;
if (key == 13) {
search_google();
}
}
function search_google(){ 
window.open("http://tr.wikipedia.org/wiki/"+document.search.query.value); 
}
</script>
<form name="search" style="text-align: center; background-color:#444577">
<div style="padding-top: 2px">
<input type="text" name="query" value="" style="font-family: Tahoma; font-size: 10pt; vertical-align:middle; text-align:center" size="16"><input type="button" value="Sözlük" onClick="search_google()" style="font-family: Tahoma; font-size: 10pt; vertical-align:middle; height:18">
</div>
</form>

[nizamo]

In short with IExplorer go to page http://www.aymavisi.org/hikaye/Dostu...%20Cibran.html and type something in search box Sitede Ara and hit enter key, you'll see two windows open. How to fix it?