Problem with basics

hi! I am trying to validate for empty input text field on a button click. Can someone tell me what’s wrong with this code:

mytext is a variable
inputvalue is variable name for the input text field

on (release) {
_root.mytext = _root.inputvalue;
if(_root.inputvalue == “”) {
gotoAndPlay(“errormsg”)
}
}

Is there a problem with the double quotes?