thanks Ulf for those motivating words
creating a md5 hash is also fine , storing it in the database is also ok.. but problem comes when i want to know if the link is accessed or not,
if its accessed once or not(for that i can use a flag variable right) ,
if the link is expired or not( for that i can check if the time > the time when the hash has been generated right).
but i just didnt get the idea how to know if the link is accessed( that is if the link has been clicked or not)
[ February 17, 2008: Message edited by: Rakesh Shah ]