function checkzip(zip)
{
 zipcodes = new Array(
 4120,
 4122,
 4130,
 4140,
 4000,
 4020,
 4030,
 4031,
 4032,
 4040,
 4041,
 4042,
 4050,
 4052,
 4051,
 4053,
 4100,
 4101,
 4102,
 4340,
 4342,
 4347,
 4400,
 4420,
 4430,
 4431,
 4432,
 4450,
 4451,
 4452,
 4453,
 4458,
 4460,
 4600,
 4601,
 4602,
 4607,
 4606,
 4608,
 4610,
 4620,
 4621,
 4623,
 4624,
 4630,
 4631,
 4632,
 4633,
 4650,
 4651,
 4652,
 4653,
 4654,
 4670,
 4671,
 4672,
 4680,
 4681,
 4682,
 4683,
 4684,
 4800,
 4801,
 4802,
 4820,
 4821,
 4860,
 4877,
 4880,
 4890,
 4690,
 4130,
 4120,
 4121,
 4870
 );
 
 for (i=0;i<zipcodes.length;i++) {
     if (zipcodes[i] == zip) {return 1;} 
 }
 return 0;
}

function zipsearch(zip){
 if (checkzip(zip)) {alert("Nous livrons dans votre commune !");}
 else {alert("Nous ne livrons malheureusement pas dans votre commune...");}
 return false;
}