Skift billede (mouse over)

Hej,

Jeg har kig på et ratingsystem:

<script type="text/javascript">
function changerating(data) {
    if (data==0) {
        document.getElementById('rate1').src='gfx/star_empty.gif';
        document.getElementById('rate2').src='gfx/star_empty.gif';
        document.getElementById('rate3').src='gfx/star_empty.gif';
        document.getElementById('rate4').src='gfx/star_empty.gif';
        document.getElementById('rate5').src='gfx/star_empty.gif';
    }
    else if (data==1) {
        document.getElementById('rate1').src='gfx/star_full.gif';
    }
    else if (data==2) {
        document.getElementById('rate1').src='gfx/star_full.gif';
        document.getElementById('rate2').src='gfx/star_full.gif';
    }
    else if (data==3) {
        document.getElementById('rate1').src='gfx/star_full.gif';
        document.getElementById('rate2').src='gfx/star_full.gif';
        document.getElementById('rate3').src='gfx/star_full.gif';
    }
    else if (data==4) {
        document.getElementById('rate1').src='gfx/star_full.gif';
        document.getElementById('rate2').src='gfx/star_full.gif';
        document.getElementById('rate3').src='gfx/star_full.gif';
        document.getElementById('rate4').src='gfx/star_full.gif';
    }
    else if (data==5) {
        document.getElementById('rate1').src='gfx/star_full.gif';
        document.getElementById('rate2').src='gfx/star_full.gif';
        document.getElementById('rate3').src='gfx/star_full.gif';
        document.getElementById('rate4').src='gfx/star_full.gif';
        document.getElementById('rate5').src='gfx/star_full.gif';
    }
}
</script>
<img src="gfx/star_empty.gif" id="rate1" onmouseover="changerating(1);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 1 stemme">
<img src="gfx/star_empty.gif" id="rate2" onmouseover="changerating(2);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 2 stemmer">
<img src="gfx/star_empty.gif" id="rate3" onmouseover="changerating(3);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 3 stemmer">
<img src="gfx/star_empty.gif" id="rate4" onmouseover="changerating(4);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 4 stemmer">
<img src="gfx/star_empty.gif" id="rate5" onmouseover="changerating(5);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 5 stemmer">


Det virker fint nok - mit spørgsmål er flg.: Hvad gør man, hvis man ikke starter med 5 TOMME stjerner? Hvis nu objektet allerede HAR en rating f.eks. på 1,5 - så kunne billeder se sådan ud:

<img src="gfx/star_full.gif" id="rate1" onmouseover="changerating(1);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 1 stemme">
<img src="gfx/star_half.gif" id="rate2" onmouseover="changerating(2);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 2 stemmer">
<img src="gfx/star_empty.gif" id="rate3" onmouseover="changerating(3);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 3 stemmer">
<img src="gfx/star_empty.gif" id="rate4" onmouseover="changerating(4);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 4 stemmer">
<img src="gfx/star_empty.gif" id="rate5" onmouseover="changerating(5);" onmouseout="changerating(0);" style="cursor:pointer;" onclick="document.location.href='noget.html';" alt="Giv dette produkt 5 stemmer">

Problemet er jo at ved mouseover skifter scriptet til en tom stjerne:
    if (data==0) {
    document.getElementById('rate1').src='gfx/star_empty.gif';


Kan man ikke ordne det sådan at den skifter til billedets oprindelige src i stedet?