function checkEnter(e){ //e is event object passed from function invocation
  var characterCode; //literal character code will be stored in this variable
  
  if(e && e.which){ //if which property of event object is supported (NN4)
    characterCode = e.which; //character code is contained in NN4's which property
  }
  else{
    if (event)
			e = event;
    characterCode = e.keyCode; //character code is contained in IE's keyCode property
  }
  
  if(characterCode == 13){ //if generated character code is equal to ascii 13 (if enter key)
    //var answer = confirm("Do you want to continue to Check Out?");
		return false;
		if (answer) {
			returnObjById("continue").submit(); //submit the form
			return false;
		}
		else return false;
  }
  else{
  	return true;
  }
}

function returnObjById( id )
{
    if (document.getElementById)
        var returnVar = document.getElementById(id);
    else if (document.all)
        var returnVar = document.all[id];
    else if (document.layers)
        var returnVar = document.layers[id];
    return returnVar;
}