function checkJoin(thisForm){
	if(thisForm.YourName.value == ''){
		alert('Please enter your name.');
		return false;
	}
	if(thisForm.YourEmail.value == ''){
		alert('Please enter your email address.');
		return false;
	}
	var email = thisForm.YourEmail.value;
	var isEmailOkay = email.indexOf('@');
	var isDotOkay=email.indexOf('.');
	if ((isEmailOkay == -1) || (isDotOkay == -1))
	{ 
		alert('Your email address must contain the @ character and at least one dot (.)');
		return false;
	}
	if (thisForm.OtherRole.checked==true){
		if(thisForm.OtherRoleDetails.value == ''){
		alert('Please enter an alternative role.');
		return false;
	}
	if (thisForm.OtherQual.checked==true){
		if(thisForm.OtherQualDetails.value == ''){
		alert('Please enter details of your other qualifications.');
		return false;
	}
	return true;
}