How to add a lookup form to a string edit control of a form

After creating your  form lookup, use this method in your string edit control to call it .

public void lookup()
{
    FormRun formRun;
    Args args;
    ;
   
    args = new Args("Thy_ProformaIdLookup");
    formRun = classFactory::formRunClassOnClient(args);
    args.parm(SalesParmSubTable.OrigSalesId);
    formRun.init();
    this.performFormLookup(formRun);
}