List box selection is not working properly

I am trying to select one option from listbox. The problem is selection is done on different element. Please check the below code for your reference

Browsers.Item(btChrome).Navigate("url");
Aliases.browser.BrowserWindow.Maximize();

var selectElement=Aliases.browser.pageSignUpForFacebookFacebook.formReg.selectMonth;
selectElement = ClickItem("Jun");

The above code is to select June but it is selecting October. Please help me out to resolve this issue. Thanks in advance.