Jquery :: Max / Min Functionality For Image Replacement

I am using jquery in my current application to add min/max functionality, i.e, when the user close at maximize, table gets maximized, when clicked on minimize, table gets minimized. It works fine functionality wise, but, ideally, when maximized, max image should replace with min image and vice-versa, but images gets replaced only when clicked 2nd time around, for very first time, images don't get replaced, though the system works fine,

Here's how I am calling the function:
<a href="javascript:void(0);" onclick="showinghide('contacting')"><img src="images/arrows/opened.gif" id="contactingarrow" class="myarrows"></a>

Here's the function:
function showinghide(oobj){
if(oobj=="contacting"){
jQuery("#contacting").toggle('slow');
mycookies("contacting");
}
And the jquery code is:
function mycookies(myobbj) {
var mycookiesvar=myobbj+"cook";
if(jQuery.cookie(mycookiesvar)){
if(jQuery.cookie(mycookiesvar)==myobbj+"hide"){
jQuery.cookie(mycookiesvar,null);
jQuery.cookie(mycookiesvar,myobbj+"show",{expires:365});
jQuery("#"+myobbj+"arrow").attr({'src':'images/arrows/open_bk.gif'})
} else if(jQuery.cookie(mycookiesvar)==myobbj+"show"){
jQuery.cookie(mycookiesvar,null);
jQuery.cookie(mycookiesvar,myobbj+"hide",{expires:365});
jQuery("#"+myobbj+"arrow").attr({'src':'images/arrows/close_bk.gif'})
}} else {
jQuery.cookie(mycookiesvar,myobbj+"hide",{expires:365});
}}