Insert/update from combobox

[Nirel]

Hi All,
i a new to access.
I have 3 tables:
tbl_1 (int_Rst_id,fld_str_name)
tbl_2 (int_Skill_ID,str_Description)
tbl_3 (int_FK_Rst_id,int_FK_Skill_ID,int_score)
and a simple form with subform. a combobox on main form from (SELECT tbl_1.int_Rst_id, tbl_1.fld_str_Name
FROM tbl_1 WHERE tbl_1.fld_int_HelpDeskResourceTypeID in (1,2)
Subform based on (SELECT tbl_2.int_Skill_ID, tbl_2.str_Description, tbl_3.int_FK_Rst_ID, tbl_3.int_score
FROM tbl_2 LEFT JOIN tbl_3 ON tbl_2.int_Skill_ID=tbl_3.int_FK_Skill_ID
I need to insert into tbl_3 selected value from a combobox and the score and skills_id from the subform
..how do I do that ?many thanks