How we use the Form_Start

When you want your code to run when you open a form or while a form is open
you use the procedure Form_Statrt.
The example below shows the basic commands. 


proc Form_Start()
     f   =
TopForm()   {this command brings the form’s id}

     pnl =
PByName(f;"CUSTOMER")    {this command brings the form’s panel id}
     tbl  =
TByName(pnl;"CUSTOMER")    {this command brings the table’s id}

     cust_id = TGetFld(tbl;”LAST_NAME”)  {this command brings a table’s column data}
     write your code (code for checking something or code for a lookup field …)