Recommended Approach

Would like to achieve the following if possible but would need some guidance on what best to use in scriptcase.

  1. Enter value in textbox which triggers a search in database and returns some values, achieved with grid lookup
  2. Would like to populate some other fields with values generated from the grid lookup
  3. Would like to compute a total based on the fields loaded in 2) and some values typed directly by the user.

Any expert recommended approach?

I know nothing about (1) & (2)

Regarding (3)
Go to programming => PHP Methods and create for example setTotal and use the following code:
{total} = {field_one}+{filed_2};

OK. now go to Ajax event and create an event for every field and use the following code:
setTotal();

  1. The closest option would be to make the field ajax text autocomplete.
  2. You can set an onchange ajax event to fill the fields or - if they are lookups- set an ajax event to refresh these after setting your first lookup