I am having a valid H1B visa till 2005 july to work in United States of America.I left the USA in 2004 May and came to home country.I am planning to come back again.Can i come back on my existing visa or do i have to get the new H1B to come back to USA?If i come back on my old existing Visa,will my clock set back to 6 years?My employer is still showing interest to take me back into the company.