function checkForm(){
//declare variables
var errmessage='';
var email = document.sendform.email.value;
var nom = document.sendform.nom.value;
var mssg = document.sendform.message.value;
var atplace = email.indexOf("@");
var lastdot = email.lastIndexOf(".");

// check email
if ((email.length == 0) || (atplace ==-1) || (lastdot < atplace) || (email.length <= lastdot+1)){
   errmessage = errmessage + "Please enter a valid email address\n";
}

// check name
if (nom.length == 0){
    errmessage = errmessage + "Please enter your name\n";
}

//check message
if (mssg.length == 0){
	 errmessage = errmessage + "Please enter a message\n";

}

// check whether the form should be sent
if (errmessage.length > 0){
	alert(errmessage);
	return false; 
}

else {
	return true;
}

}