function validate_form(){
    var errors = '';
    
    if(document.contactForm.first_name.value == ''){
    	errors += "- The First Name field is mandatory.\n";
    }
    if(document.contactForm.last_name.value == ''){
    	errors += "- The Last Name field is mandatory.\n";
    }
    
    if(document.contactForm.email.value == ''){
    	errors += "- The Email field is mandatory.\n";
    }
    if(document.contactForm.hear.options[document.contactForm.hear.selectedIndex].value == 'Choose One...'){
    	errors += "- The 'Where did you hear about us' selection is mandatory.\n";
    }
    if(document.contactForm.phone.value == ''){
    	errors += "- The Phone field is mandatory.\n";
    }

    if(errors) {
    	alert('The following error(s) were encountered:\n' + errors);
    	return false;
    }

    return true;
}