How to fetch the selection of pop-up menu and then zoom out?

How can I fetch the selection of a p开发者_JS百科op-up menu after the user has selected "his" item and then pressed "Done"?

The selected can be displayed with:

 var clicked = document.getElementById("popup").value;  

alert(clicked);

And, how can I zoom out, after this item has been selected?

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I have put a "ChangeHandler" on the pop-up men

function myChangeHandler(event) {

var clicked = document.getElementById("popup").value;
alert(clicked);

}

BR,

Stefan