Plaque d'immatriculation

var keyCode = (window.event) ? e.which : e.keyCode;

<input type="text"  id="plates" placeholder="AA-123-AA" onkeyup="envoilabel()" pattern="^[A-Z]{2} ?- ?\d{3} ?- ?[A-Z]{2}$" />

$(document).ready(function(){
	function check(s) {
	    var toks = s.split('-');
	    //console.log(toks);
	    switch(toks.length){
	        case 3:
	        if (!/^[A-Za-z]{0,2}$/.test(toks[2].trim())) return false;
	        case 2:
	        if (!/^\d{0,3}$/.test(toks[1].trim())) return false;
	        case 1:
	        return /^[A-Za-z]{0,2}$/.test(toks[0].trim());
	        default:
	        return false;
	    }
	}
	var oldvalue = '';
	$('#plates').keyup(function(e){
	    if (!check(this.value)) {
	        this.value = oldvalue;
	    } else {
	        oldvalue = this.value = this.value.toUpperCase();
	    }
	    if (!e) {
	        e = window.event;  // Get event details for IE
	        e.which = e.keyCode; // assign which property (so rest of the code works using e.which)
	    }
	    if((this.value.length==2 || this.value.length==6) && (e.keyCode!=8)){
	            this.value=this.value+"-";
	    }
	});

});