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)
		e = e
		characterCode = e.which //character code is contained in NN4's which property
		}
		else{
		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)
		document.forms[0].submit() //submit the form

		return false
		}else{
		return true
		}

}