function check_form(){
	var str = "";


	if (document.cform.yname.value == "" || document.cform.yname.value=="Your name") {
		str = str + " Name \n";
	}	
	if ( (document.cform.email.value == "" || document.cform.email.value == "Your email address" ) &&  (document.cform.phone.value=="" || document.cform.phone.value=="Phone")) {
		str = str + " Phone or Email \n";
	}		
	if (document.cform.please_send_me.value == "yes" && (document.cform.contact_time.value=="Preferred time and date" || document.cform.contact_time.value=="")) {
		str = str + " Preferred time and data \n";
	}	
	

	if ( document.cform.email.value.length > 0 && document.cform.email.value != "Your email address" && ( document.cform.email.value.indexOf("@",0) == -1 || document.cform.email.value.indexOf(".",0) == -1 ) ) {
			str += " a valid email \n"	;
	}

	 if(str == ""){
		  document.cform.action = "contactform.php";
		  document.cform.submit();
	 }
	 else {
			alert("Please fill in the following  :\n" + str);
	 }
}