Problem to connect internet sometime !!!

Hello,
Need a help. I am having win vista business adition on my laptop. I am using wireless router at my company. when i want to search a webpage the problem comes. some time the website will open and some time it will not open. most of the time i am not able to open website. The explorer will be blank. Its not happening when i am using the same laptop at my home. So in this matter what i want to do? I am getting the full signel of wireless router after that also the problem was still. Can anyone help me out in this matter?

Regards,
Shashank