Did you remember to assign a value to the custom control properties? (on the form containing the control) This is required so that EnsureChildControls is called.

This is what I did with your control, and it worked fine:

paste the code into a Web Control Library new project (changed the namespace to the default of the project)

build that project

add the control to the toolbox (right-click on toolbox, Customize Toolbox, .Net Framework Components, Browse)

drag the SearchControl into a Web form of another project

set a value to the "SearchProcedure" property

build and run the web project

...and on click I was redirected to www.microsoft.com as you intended

Regards,
Jose.