I am creating a form in which a checkbox is checked based on the info from previous page.
The info I am passing is the client ID (which is a number I can pass in the URL variable)
In the form I have a list of clients (with checkboxes next to them)
Now if you come from a specific client page the checkbox with the client name should be already checked since you are getting info regarding that client, with the option of selecting other clients..
You should submit the first form to a server-side script, such as PHP, so that the server-side script can then build the next page with information from the previous page.