Functions Prototyping

Callout Method is Definedby function as prototype function, Explained below. 

calloutClass.prototype.set = function (ctx, windowNo, mTab, mField, value, oldValue) { 

//your logic 

return ""; 

}; 

Basically this callout method will bind with a particular column and the logic defined in the method will execute on lost focus of particular field. 

In the same way you can create multiple callout method and bind with columns. 

Example: 

TestClass.prototype.set = function (ctx, windowNo, mTab, mField, value, oldValue) { 

if (this.isCalloutActive() || value == null ) { 

return ""; 

} 

this.setCalloutActive(true); 

mTab.setValue("Description", value); 

this.setCalloutActive(false); 

return ""; 

}; 

Callout parameters defined in next section