Hello Rathi, Marek, Vanguarda, Swapan, Esgici,
Thanks a lot for your kind words
Previously I thought using SQL cannot be as fast as using DBFCDX. But, recently after changing coding style (learning from Rathi's code), I found using SQL is as fast (if not better

) using DBFCDX.
Too much GUI makes a program slow.
For writing programs, previously I thought control names like "txtInvdt" is better to show this is a textbox, or "cboCustid" is better for a combo box. But, writing codes using "invdt" as textbox and "custid" as combobox for 2 days, I found there is not very much problem to understand the logic. Code became smaller and typing time also got reduced
I also found when we want to run some code at the starting of a window, it's better to put the code beteen END WINDOW and .... ACTIVATE WINDOW commands, than using ON INIT method.
When using SQL, it's always better to run the SQL commands at a time, than call different SQL commands separately.
Here I only expressed some of my findings. I may be wrong, as I am learning this software tool. So, please correct me, if you find any BUG in my views.
With best regards.
Sudip