I cam across a strange situation where the page of my SharePoint website just refreshes itself when I search on my site using the Enter key. I noticed this was only a problem when I use Firefox.

On Goggling I found following solutions

http://social.msdn.microsoft.com/Forums/en-US/sharepointecm/thread/87574c13-91d6-48fe-8346-01e77e0094b3

http://blog.drisgill.com/2009/08/firefox-doesnt-respond-to-enter-key-in.html

http://blogs.msdn.com/b/jjameson/archive/2009/10/01/enter-key-does-not-submit-search-in-moss-2007-from-firefox.aspx
I modified the solution by Jeremy Jameson, to suit my requirements.

    <script language="javascript"> function replaceOnKeyPress()
    {
    var theInputID = $("input[name$='InputKeywords']").attr("id");
    if(typeof(theInputID) != "undefined")
    {
    var theFunction=theInputID.replace("InputKeywords", "");
    var LastindextOf =theFunction.lastIndexOf("");
    if (LastindextOf >0)
    {
    theFunction=theFunction.substring(LastindextOf+1,theFunction.length);
    theFunction = theFunction + "_Submit();";
    var txt = document.getElementById(theInputID);
    var browser = navigator.appName;
    if (txt && (browser == "Netscape"))
    {
    txt.onkeypress = function(e)
    {
    var key = String.fromCharCode(e.keyCode);
    if (key == "\n" || key == "\r")
    {
    eval(theFunction);
    return false;
    }
    }
    }
    }
    }
    }
    replaceOnKeyPress();
    </script>