java - comparison of two Strings doesn't work in android

here's my code, Eclipse doesn't show any errors, program's
working fine, but it simply doesn't do exactly what i want:)

 View image_view_danger_rate =
            (ImageView) findViewById(R.id.origin);
 View image_view_origin = (ImageView)
            findViewById(R.id.danger_rate);

 String entry_tag = (String)
            descriptionResultView.findViewById(resID).getTag();

 String
            dangerous = "dangerous";
 String not_dangerous =
            "not_dangerous";

 if ( entry_tag == dangerous) {

            image_view_danger_rate.setBackgroundResource(R.drawable.attention);
 }else if
            ( entry_tag == not_dangerous) {

            image_view_danger_rate.setBackgroundResource(R.drawable.its_ok);

            image_view_origin.setBackgroundResource(R.drawable.artificial);

            }

The application
should choose between two images to pop-up on the screen, depending on a tag stored in
the xml file.
So, if the tag says "dangerous", then should be shown the
"attention"-image.
If the tag says "not_dangerous", there should be the
"its_ok"-image.

Now, displaying the images
without an if-comparison works perfectly.

If i
print out the tags as a string, it works, it prints correctly "dangerous" or
"not_dangerous", depending on the tag.

But if
there's a if-comparison as shown above, nothing happens, no image is
shown.

Please anyone
help!!=)