// function to assign a default submit button to a form
// button has to have the CSS class defaultSubmit set
function assignDefaultSubmitButtons(){
  $j("form").each(function() { // loop throug all forms on the page
        var _form = this;
        var _defaultSubmit = _form.getElementsByClassName("defaultSubmit"); // search default submit button 
        if(_defaultSubmit!=null && _defaultSubmit.length>0){
          $j("input", _form).keypress(function(e){ // attach onkeypress event listener for each input field
            var keycode;
                if (window.event) {//IE
                    keycode = window.event.keyCode;
                }else if (e) {  //FF
                    keycode = e.which;
                }else {
                    return true;
                }
                if(keycode==13){
                    _defaultSubmit[0].click();  // emulates click on defaultSubmit button
                    return false;   // stops propagating keypress event
                }
          });
        }
   });
}