updating values in material master table

Hi,

I have few records in the o/p and the checkboxes were placed besides each record.If the user wants to change the data of some fields in a record,then he clicks the checkbox besides that particular record and click on the change button.Then the control goes to update screen.In this screen the user changes the values of the fields of which he wants to change and click on the execute button.Then the changed values should get updated in the material master table.

I have created the update screen.Now how can I write the logic for the changed values to get updated in the material master table?

Regards,

Hema