How to handle the result of a Client Method called with evalMethod

Hi, I have various Javascript Methods that all shall call one specific Javascript Method which contains some validation rules. I wonder what the best way, to retrieve the result of this Validation Method. The Validation Method will return an AlertError when something went wrong (e.g. when Users doesn´t have necessary permission.). If the Validation Method fails, the other Methods shall not continue their work. What´s the best way to handle the result of Javascript Methods? This one is my current approach, but I don´t know if it´s fully reliable: Method 1: MainMethod

var relId = this.getID();
var relType = this.getType();
var result = aras.evalMethod("MyValidations", this); // call validation Method
if (typeof result == "object" ) {
   	return null; // abort main function
} 
// run main Method

Method 2: MyValidations

var thisItm = inDom;
var relId = thisItm.getID();
var relType = thisItm.getType();
if (relType == "Part"){
	return aras.AlertError("Not possible");
}
return; // = no Object

Any feedback welcomed! Angela