Ok ecco qui il codice:
codice:
<body onload="inti();">
<form...>
<input type="text" id="idUser" name="username"
placeholder="cellulare (10 numeri)"/><lable id="euser"></lable>
</form>
</body>
<script>
function init(){
//inizializzo variabili
}
var idusr = document.getElementById("idUser").addEventListener("keydown", KeyCheckUsr);
function KeyCheckUsr(event)
{
var KeyID = event.keyCode;
BtnOnOff(KeyID,"usr");
}
function BtnOnOff(keyID, type){
if (type=="usr") {
vuser = document.getElementById("idUser").value.trim();
document.getElementById("idUser").value=vuser;
if (keyID==8 && vuser.length>0) lenuser = vuser.length-1;
else if (keyID>=48 && keyID<=57)
lenuser = vuser.length+1;
document.getElementById("euser").innerHTML = " solo numeri ["+lenuser+"]";
}
}
</script>