function ctrlsaisie(emailfield) {

if (document.ctrlform.namefield.value==""){
       alert("\nVeuillez compléter le champ 'nom'.")
      document.ctrlform.namefield.focus()
       return false
     }

if (document.ctrlform.firstnamefield.value==""){
       alert("\nVeuillez compléter le champ 'prenom'")
      document.ctrlform.firstnamefield.focus()
       return false
     }

var a=document.forms[0].emailfield.value;
var test="" + a;
for(var k = 0; k < test.length;k++)
{
var c = test.substring(k,k+1);
if(c == "@")
	{
	return true;
	}
}
alert("\nVeuillez compléter le champ e-mail");
return false;

}