"Lost Focus" event on web form text box

yes, it is possible

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwindowsformscontrolclasslostfocustopic.asp

apologies... that tutorial is for regular forms.
It is possible however, but i read that you have to capture the exitFocus event of the input box... I will try and track down the page again.

Thank you for that but is there anyway I can hook up the Javascript so I can handle code behind functions.

Ideally I need to capture the "loose focus" event so that it runs a c# code behind function.

Could anyone suggest an alternative approach - I need to capture the "loose focus" event on a c# web form