function Validate() {
Message = ""
Message = Message + CheckFirstName()
Message = Message + CheckLastName()
Message = Message + CheckEmail()

if (Message == "") {
return true
}
else {
alert(Message)
return false
}

}


function CheckFirstName() {
UserName = document.forms['f1'].FirstName.value

if (UserName == "") {
Message = "Your First Name field is empty" + "\n"
}
else {
Message = ""
}
return Message

}

function CheckLastName() {
UserName = document.forms['f1'].LastName.value

if (UserName == "") {
Message = "Your Last Name field is empty" + "\n"
}
else {
Message = ""
}
return Message

}

function CheckEmail() {
email = document.forms['f1'].Email.value
AtPos = email.indexOf("@")
StopPos = email.lastIndexOf(".")
Message = ""

if (email == "") {
Message = "Your Email address is not valid" + "\n"
return Message
}

if (AtPos == -1 || StopPos == -1) {
Message = "Your Email address is not valid" + "\n"
return Message
}

if (StopPos < AtPos) {
Message = "Your Email address is not valid" + "\n"
return Message
}

if (StopPos - AtPos == 1) {
Message = "Your Email address is not valid" + "\n"
return Message
} 

return Message;
}