any one can help please???

Question

hello every one 

i have three forms

form1 is Mainform

form2 is Lockform

form3 is Settingform

 

in Settingform i put a checkbox to let the user  choosing if he wants to cancel lockform and load Mainform or not cancel it and keep lockform and as u see in pic and i tried many ways no one worked and now i have no idea please help