Not case sensitive input of username?

I have a login section that has a username and password input field. I am not sure if I am doing this right, but since there is only one username and one password, this is how I did this.

function checkPassword(userN:String, passW:String):Void {
if(userN == “collections” && passW == “winter2008”){
//let user proceed
//error message

My question now is how can I have the username not be case sensitive. Is that possible?

Thanks a lot for any help!