Thanks for your reply for my question
When text is selected and clicked on the bookmarklet it opens a new tab and does an exact search with the snippet of the text selected using google.com/search?q="(myselected text)"
Now i want it to do automatically on a key press
When certain text is selected and selected key is pressed it should do the work as when i clicked on the bookmarklet.
Note: I'm using this bookmarklet in CHROME