function checkValidForm(){
	// check first, middle va last Name
	if(this.document.StudentInformation.FirstName.value==""){
		alert("Please specify your first name.")
		return false
	}	
	if(this.document.StudentInformation.MiddleName.value==""){
		alert("Please specify your middle name.")
		return false
	}		
	if(this.document.StudentInformation.LastName.value==""){
		alert("Please specify your last name.")
		return false
	}
	
	// check phone home
	if(this.document.StudentInformation.HousePhone.value==""){
		alert("Please specify your home phone.")
		return false
	}
	
	// checkbirthday
	if(isValidDate(this.document.StudentInformation.BirthDay.value)==false){
		return false
	}

	// check email
	if(checkEmail(this.document.StudentInformation.Email.value)==false){
		return false;
	}
	
	// check country
	if(this.document.StudentInformation.Country.value==""){
		alert("Please enter your country.")
		return false
	}
	

	// check course 
	if(this.document.StudentInformation.Course.value==""){
		alert("Enter your course, please.")
		return false
	}
	// check schoolname
	if(this.document.StudentInformation.SchoolName.value==""){
		alert("Enter your school name, please.")
		return false
	}
	
	// check startTime and EndTime
	if(this.document.StudentInformation.StartTime.value==""){
		alert("Enter StartTime, please.")
		return false
	}
	if(this.document.StudentInformation.EndTime.value==""){
		alert("Enter EndTime, please.")
		return false
	}
	// check relation of starttime and endTime
	if(Date.parse(this.document.StudentInformation.StartTime.value)>=Date.parse(this.document.StudentInformation.EndTime.value)){
		alert("StartTime and EndTime is not valid")
		return false
	}

	// check security question
	if(this.document.StudentInformation.Answer.value==""){
		alert("Enter answer the security question, please.")
		return false
	}
	
    return true
}
function checkEmail(strEmail){
	validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
	if (strEmail.search(validRegExp) == -1) 
	{
		alert(" A valid e-mail address is required.\r\Please check that you have entered your details correctly.");
		return false;
	}			
	return true;
}

// function check validation date
function isValidDate(dateStr) {
// Checks for the following valid date formats:
// MM/DD/YY   MM/DD/YYYY   MM-DD-YY   MM-DD-YYYY
// Also separates date into month, day, and year variables

var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{2}|\d{4})$/;

// To require a 4 digit year entry, use this line instead:
// var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{4})$/;

var matchArray = dateStr.match(datePat); // is the format ok?
if (matchArray == null) {
alert("You didn't specify a valid birthday, for example: 08/30/1969.")
return false;
}
month = matchArray[1]; // parse date into variables
day = matchArray[3];
year = matchArray[4];
if (month < 1 || month > 12) { // check month range
alert("Month must be between 1 and 12.");
return false;
}
if (day < 1 || day > 31) {
alert("Day must be between 1 and 31.");
return false;
}
if ((month==4 || month==6 || month==9 || month==11) && day==31) {
alert("Month "+month+" doesn't have 31 days!")
return false
}
if (month == 2) { // check for february 29th
var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
if (day>29 || (day==29 && !isleap)) {
alert("February " + year + " doesn't have " + day + " days!");
return false;
   }
}
return true;  // date is valid
}