Need to select the records which are same purchid's in purchlineopenOrder form

Dear friends,

                    I'm new to microsoft dynamics AX,Actually i need a small help.I duplicated the PurchlineOpenOrder Form  and set the datasources in it as allowedit as yes because its a non-editable form.As we know in purchlineopenorder we can see records of purchlines of same purchid's.Now i created the customized field of (OK)check box with EDT noyesId in purchline table and drag and dropped that field to grid in the form. So,my customization is if i check (OK) for one purchline of purchid the remaining records of same purchid have to be checked as well...Please help me out...:)