function cek(){

	var nameFirst=document.getElementById('name_first').value;
	var nameLast=document.getElementById('name_last').value;
	var emailAdd=document.getElementById('email_add').value;
	var regType=document.getElementById('reg_type').value;
	var companySchool=document.getElementById('company_school').value;
	var address=document.getElementById('address').value;	
	var phoneDay=document.getElementById('phone_day').value;
	var resume=document.getElementById('resume').value;

	if(regType=='Professional (Sponsor Company)' || regType=='Professional (Other Company)' || regType=='HBS Alumnus') { // condition for professional/alumni registration types

		if(nameFirst=='' || nameLast=='' || emailAdd=='' || companySchool=='' || address=='' || phoneDay==''){
			alert("Please complete the required fields");
			return false;
		}else{
			return true;
		}	

	} else { // condition for other registration types

		if(nameFirst=='' || 
		    nameLast=='' || 
			emailAdd=='' || 
			regType=='' || 
			companySchool=='' || 
			address=='' || 
			phoneDay=='' || 
			resume=='' || 
			(!document.register.resume_agree.checked)
			){
			alert("Please complete the required fields");
			return false;
		}else{
			return true;
		}	

	}

}