child table can not be updated

Question

I want to add 3 text boxes values in single table at one time...For this purpose i m using for loop but its giving me eror after inserting first value that the cant update or add the child row...what should i do now....my query is given below. 

 

 

 

TextBox[] textBoxes = new TextBox[] { textBox5, textBox6,textBox7 };

try

{

for (int i = 1; i <=3; i++)

{

cmd = connection.CreateCommand();

cmd.CommandText = "INSERT INTO RequirementSkill(ReqSkillName,fk_ReqID)VALUES(@ReqSkillName,LAST_INSERT_ID())";

cmd.Parameters.AddWithValue("@ReqSkillName", textBoxes[i].Text);

cmd.ExecuteNonQuery();

cmd.Parameters.Clear();

}

}

catch (Exception)

{

throw;

}