Javascript per completamento text input

[Vindav]

function isNumber(event){
    var unicode = event.charCode? event.charCode : event.keyCode
    var c = String.fromCharCode( event.charCode ? event.charCode : event.keyCode ); 
    return ( ("0123456789").indexOf(c) != -1 || (unicode >=96 && unicode <= 105));
}