I am having a problem, I am trying to setup a random id generator with php and mysql. I want it so that when people purchase the product it gives them a download link but I do not want them to have the link for ever. I want the link to last like 30 minutes. So what I want to do is make it do is when the product is purchased it last 30 minutes but then it cancels out and it gives the file a new ID. Can anyone help me? I am lost so far. Here is what I got so far.