how to get value from querystring

hi everybody,
i am having a problem and that is
" how to get value from QueryString, and use that value, in the hyperlink control(which is placed on the html
 side) to navigate to another page"i actualy want to display, details of a particular record,on the basis of
that value(which is coming from QueryString) through hyperlink,because i want to open that page in new
window(using the feature of hyperlink i.e Target="_blank").

Thanks in advance, i realy apreciate your response.

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