what is user control?

These are like .aspx pages.The extension is .ascx.It supports caching mechanism in the project.We can also create our own user control and add them in the tool box as how we have in our toolbox.

Urgent Variable in SSIS package?

How to use global variable in Microsoft SSIS (DTS) package

http://www.codeproject.com/useritems/global_variable_in_SSIS.asp

y autoeventwireup attribute will be set to false?

http://www.codeproject.com/aspnet/AutoEventWireup.asp

what is the major difference between 1.1 an 2.0?

http://msdn2.microsoft.com/en-us/library/t357fb32(VS.80).aspx