Please Help: how to customize this

Hi all,
I want to use dhtmlxGantt to make audit team schedule.
The variable that i want to enter on the input are:
Auditor ID
Auditor Name (which will replace the “Project”), the auditor name will be generated from auditor database
Auditor Project (which will replace the “Task”), the task will be generated from dropdownlist

I want to customize the input so that when i input one task and i enter the teams member. All the team will have the task on their schedule.

How can I connect to my sql server database and how can i modify the input box (i am using ASP.NET Webform) ?

For more explanation I attach the image: