function Trim(value) {
    value = String(value);
    return value.replace(/^\s+/ig, "").replace(/\s+$/ig, "");
}

function IsValidUrl(objId){
    obj = document.getElementById(objId);
    if(obj.value == '') {
        return false;
    }
    obj.value = Trim(obj.value);
    var re = new RegExp("^https?://", "i");
    if(!re.test(obj.value)) {
        obj.value = 'http://' + obj.value;
    }
}