InfoPath Dev

This form would be for our locations to select their location - the customer number & the container number - when they hit submit button, I want it to find that record in the sharepoint site & update the field "TimeStamp" to show Username & Time & Date that the button was pressed.

Would that be the same as using a rule on submit & use the "run query" then "submit data"?

Sorry for my ignorance - 1st time working with infopath!

In the same list

I have a form called "TimeStamp Form" that will look into my sharepoint to verify the information and if it is equal then when I press the button I want it to update the field in the Sharepoint list in the field TimeStamp. I would like it for the timestamp to be the "Username" & "Now". Any help would be greatly ...