Use the attachevent ()/addeventlistener () method to add a trigger event

In recent work, the attachevent method is used. This method can append other processing events to an event, which may be useful sometimes. Here we will summarize its basic usage.

For more information about its syntax, see the DHTML manual. Here is an example from the Internet:

Document. getelementbyid ("BTN"). onclick = Method1;
Document. getelementbyid ("BTN"). onclick = method2;
Document. getelementbyid ("BTN"). onclick = method3;
If this is the case, only medhot3 will be executed.
Write as follows:
VaR btn1obj = Document. getelementbyid ("btn1 ");
// Object. attachevent (event, function );
Btn1obj. attachevent ("onclick", Method1 );
Btn1obj. attachevent ("onclick", method2 );
Btn1obj. attachevent ("onclick", method3 );
The execution sequence is method3-> method2-> Method1

If the Mozilla series does not support this method, you need to use addeventlistener.
VaR btn1obj = Document. getelementbyid ("btn1 ");
// Element. addeventlistener (type, listener, usecapture );
Btn1obj. addeventlistener ("click", Method1, false );
Btn1obj. addeventlistener ("click", method2, false );
Btn1obj. addeventlistener ("click", method3, false );
The execution sequence is Method1-> method2-> method3