javascript validate that one of two fields has a value

  
function IsEmpty(atextfield, btextfield) {
   if ((atextfield.value.length==0) ||
   (atextfield.value==null)) {
   ((btextfield.value.length==0) ||
   (btextfield.value==null))
	  return true;
   }
   else { return false; }
} 
function chkcontact()
{
   if(IsEmpty(form2.U_EMAIL, form2.U_PHONE)) 
   { 
   alert('You have not entered a contact method!')
   document.form2.agreecheck1.checked = false;
  return false; 
   } 
 
agreesubmit();
return true;
 
} 

  
function IsEmpty(atextfield, btextfield) {
   if ((atextfield.value.length==0) || (atextfield.value==null) ||
      (btextfield.value.length==0) || (btextfield.value==null))
	  return true;
   }
   else { return false; }
}