Javascript Clonenode() - get element by id?

I am fiddling with this javascript code here

http://jsfiddle.开发者_高级运维net/7Sd4W/4/

I am trying to get it to clone a select element with ID = "sel0"

Then when It clones it I want it to create the same select element but with "sel+i" , i increments meaning everytime its cloned

The ids would be sel0,sel1,sel2,sel3,sel4 etc..

I tried changing

document.getelementsbyID()

or

document.getelementsbyname()

However it does not seem to work

Thanks

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var copy = orig.cloneNode(true);
copy.setAttribute("id", modify(orig.getAttribute("id")));
document.body.appendChild(el)

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getElementsByTagName works. You can also assign a unique ID to the node before appending it (duplicate IDs can cause all kinds of issues):

See http://jsfiddle.net/7Sd4W/9/