function check_feedback_form(theForm, errMsg1, errMsg2, errMsg3) {
	if ( theForm.sendername.value == '' ) {
		alert(errMsg1);
		return false;
	}

	if ( (theForm.senderemail.value.indexOf(".") <= 2) || (theForm.senderemail.value.indexOf("@") <= 0) ) {
		alert(errMsg2);
		return false;
	}
	
	if ( theForm.content.value == '' ) {
		alert(errMsg3);
		return false;
	}
	
	return true;
}
function check_register_course_form(theForm, errMsg1, errMsg2, errMsg3) {
	if ( theForm.sendername.value == '' ) {
		alert(errMsg1);
		return false;
	}

	if ( (theForm.senderemail.value.indexOf(".") <= 2) || (theForm.senderemail.value.indexOf("@") <= 0) ) {
		alert(errMsg2);
		return false;
	}
	
	if ( theForm.senderphone.value == '' ) {
		alert(errMsg3);
		return false;
	}
	
	return true;
}