Thank you for your prompt answer, but I am still confused that 1) based on the I-797A, Notice of Action-Approval notice: Class H1B valid from xx/xx/2008 to xx/xx/2011 by USCIS, why I cannot work to 2001? 2) Can I tour to Canada or Mexico to get an H1B visa? Does it have time limit for stay in Canada or Mexico?
Thanks,
Naomama