function check(){
 	for(i=1; i<=5; i++){
	inp = document.forms[0].elements[i];
		if(!inp.value){
		alert('All fields are required.');
		return false;}
	}
return true;
}

function appt(){
sbjct = document.forms[0].elements['subject'];
sbjct.value = "Appointment"; 
}

function form_set(){	
document.forms[0].onsubmit = check;		//sets form eventhandler onsubmit. 
document.forms[0].elements[0].onclick = appt;	//sets "subject_choice" radio eventhandler onclick.
}

window.onload = form_set;