not able to finde event of diynamically created checkBox

Hi to all,
here is my problem...i am desigining an application where i m creating checkBox (not checkBoxList) dynamically.There is one master  check box that define group if i click that it should click all subCheck box under it.I am using ajax in my application.
i am able to generate check box at runtime but not able to find its event
here is the code for creating check box and its event

//This define master check box

CheckBox MstChk = new CheckBox();
MstChk.ID = Str_Header;
MstChk.AutoPostBack = true;
MstChk.CheckedChanged += new System.EventHandler(MstChk_CheckedChanged);

//This define subCheck Box under that master

 CheckBox Chk = new CheckBox();
 Chk.ID = DT_Privl.Rows[i]["V_PrivlCode"].ToString();
 Chk.Text = DT_Privl.Rows[i]["V_PrivlDesc"].ToString();
 Chk.CheckedChanged += new System.EventHandler(SubChk);

at page load i am calli ...