Custom Button to Populate Date Field

Custom Button to Populate Date Field

Completely new to Zoho, and am just starting to get my feet wet with custom buttons and scripts. So apologies in advance for the n00b question, but I've been pouring over documentation and the forum and just can't find the answer I'm looking for. Likely because it's that basic.

I'd like to create a custom button that simply fills a date field (e.g. "Requested On") with the current date, for a Lead.

I'm only sort of grasping the syntax, and am failing miserably otherwise. Any guidance that might help set me on the right track would be much appreciated.