remove timestamp from date

I want to use a cell that has a date as a vlookup value but the problem is that it fails to find the match because it has a time also included in the cell.
The cell is already formated as 'date'.

What is the best method to remove the time portion from that cell?
Example cell below:

3/14/2008 5:24:20 PM

In your VLOOKUP try using something like:

=VLOOKUP(INT(A1),$C$2:$D$100,2,0)

where A1 holds the date/time value. As far as Excel is concerned, dates are whole numbers between 0 (Jan 1, 1900) and some large number. Time is a decimal number between 0 and 1, to account for percentage of the day. So INT(A1) will return just the date portion of that value.

totally worked.