Drop down: Tool tip for each item

Hello

I have a drop down with, say, following values. But width of drop down can show only First Five characters. How can i implement such that when user scrolls to an item i should show full value as tool tip.

AAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCC
DDDDDDDDDDDDDDDD
XXXXXXXXXXXXXXXX
YYYYYYYYYYYYYYYY
ZZZZZZZZZZZZZZZZ

Thanks
Vijay

 
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