Email validation in Servicenow

1. function validateEmailAddress(emailStr){
     // Use JavaScript coercion to guarantee emailStr is a string
     emailStr = emailStr + '';
     // Compare emailStr against the allowed syntax as specified in the regular expression
     // If emailStr has allowed syntax, return true, else return false
     if(emailStr.match(/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/)){
      return true;
     }
     else {
      return false;
     }
    }

Use the Script Include in a Business Rule

1. // Pass the Requested for email to the Script Include.  Store the return
    // value from the Script Include in the isEmail variable
    var isEmail = validateEmailAddress(current.u_requested_for_email);
    // If isEmail is false (email address syntax is not valid) do not save
    // the record.  Write an error message to the screen.
    if(isEmail == false){
     gs.addErrorMessage(current.u_requested_for_email + " is not a valid email address.  You must provide a valid email address.");
     current.setAbortAction(true);
    }

2. Click the Update button.