1. When do you modified MEDRUCK? ( IF I SAID I HAVE WORKED ON SCRIPTS).
Generally, we modify existing sap scripts provided by SAP rather than creating one. Unless you have to do something new for your client like Labels or Packaging card, etc., MEDRUCK is the form for PO.
2. I want to know the procedure to create a purchase order using MEDRUCK.
You don't create a PO using MEDRUCK. MEDRUCK is the form used to print a PO that has been created.
3. What are the usual changes to be done on MEDRUCK?
Goto SE71, there is an option in Utilities as COPY ffrom Source client (000). Copy the from MEDRUCK into a Zname form. The common changes wud b inserting a logo, using Std text for Terms and Conditions, alignment of windows as per client requirement, get xtra data if client is asking for somethign more.
4. How can I access my data from DB to SCRIPTS?
There are structures used in Scripts which hold the data entered by the user. These structures are used to get data from Database.
5. Please send me the one examples in full length.
Look at MEDRUCK form and it would have a print program. you can find in tcode NACE.