If statement not working? AS3

I'm making a program that takes a user input and then if it guesses the correct letter, it display that one. I've made symbols invisible, and written a if statement to show the letters once the correct letter has been detected.

if(hangmanInput.text = "h") {
    letterH.visible = true;
    hangmanInput.text = "";

} else if(hangmanInput.text = "m") {
    letterM.visible = true;
    hangmanInput.text = "";
}

However, h works but m doesnt. Any help would be great. I get the error about not using ==, but that means the h doesnt work either.