I've tried to make it very adaptable. Look at the source of this page.
As you see, you can change the 3x9 tags, and the original name in the textfield.
in the textfield of the person that the greeting card is send to.
All labels and pictures you can also change (for pictures see further).
This way you can even make it into another sort of meter, like strength, intelligence,...
For exemple with strength: label1="yourself", label2="in a fight", label3="your name", label4="his name",
original="Ghenhis Kahn", Name1="Samson", Name2="Hulk Hogan",...
The labels has a definied lenght, if you want for exemple label1="Hello this is a very long text so it wont fit into the entire checkbox",
You 'll only see a part of it.

To change the backgroundcolor you need to alter the BgColor parameter, like in html (from 000000 to ffffff).
But then you 'll need to change some pictures, like the hearts and LoveLabel.jpg.
The text and border colors can also be changed with the parameters FgColor and BorderColor.

The pictures need to be in the same directory as the applet.
To change the pictures (width,height):
LoveLabel.jpg (360,50) is the picture with "Lovemeter" on top.
Dia0.jpg (250,200) the first picture shown, in the original "welcome to the lovemeter".
Dia1.jpg until dia27.jpg (250,200) the pictures shown with each result.
Heart0.gif until Heart4.gif (50,50) the animation on top.

You can also change the animations. As you can see in the source of this page, there is AniNrFrames and AniSpeed as parameters. AniSpeed set how long it has to wait to show another frame of the animations.
AniNrFrames sets the number of frames AND the way to cycle trough them. By example: AniNrFrame="5", then it will show Heart0.gif, Heart1.gif,...,Heart4.gif,Heart0.gif,...
But with AniNrFrames="-5" it will show Heart0.gif, Heart1.gif, ..., Heart3.gif, Heart4.gif, Heart3.gif,... Heart1.gif, Heart0.gif, Heart1.gif,...
Animated gif do NOT work.
Warning: if you set for example AniNrFrames="15", it will use Heart0.gif until Heart14.gif

The applet itself is 4 classes: Love.class, Doek1.class, Doek2.class and Doek3.class.
Love needs the other 3 to show the animated Hearts, thermometer and the picture.