Validation of Url

function validateUrl() { obj=document.getElementById(‘txtUrl’); msg=”Enter valid url”; var urlStr = /^\http\:\/\/[a-zA-Z]{3,}\.[a-zA-Z0-9]{2,} (\.[a-zA-Z]{2,3}|\.[a-zA-Z]{2,3}\.[a-zA-Z]{2})$/; if (urlStr.test(obj.value) == false) { alert(msg); obj.focus(); obj.select(); return false; } return true; }