radio buttons if then else

hi after having been giving great help the othe rday i have one more problem i would like to ask about. im trying to use a function to work out which radio button has been selected. I dont really fully understand functions so i hope i have set this out right . Anyway its not working and errors appear on the page.

am i close?

<form name="payment">
<div align="center">
  <table border="0" height="74" width="371">
    <tr>
      <td height="12" width="600">
        <p align="right"><font size="2">I'm buying a £0.50 photo&nbsp;
        (1600 x 1200)</font></p>
      </td>
  <center>
      <td height="12" width="26"><input type="radio" value="V1" checked name="R1"></td>
      <td height="12" width="29">&nbsp;&nbsp;</td>
    </tr>
  </center>
    <tr>
      <td height="25" width="600">
        <p align="right"><font size="2">I'm buying a £1.00 photo (2048
        x 1536)</font></p>
      </td>
  <center>
      <td height="25" width="26"><input type="radio" name="R1" value="V2"></td>
      <td height="25" width="29"><font size="2">
      
      <img border="0" src="x-click-but23.gif" align="center" width="68" height="23" onclick="decision(<V1>,<V2>,<V3>)">

      </font></td>
    </tr>
  </center>
    <tr>
      <td height="25" width="600">
        <p align="right"><font size="2">I'm buying a Image CD costing
        £6.00</font></p>
      </td>
  <center>
      <td height="25" width="26"><input type="radio" name="R1" value="V3"></td>
      <td height="25" width="29"></td>
    </tr>
  </table>
  </center>
</div>

<p align="center"><font size="2">&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</font>
</p>
<script type="text/javascript">
      <!--
function decision(V1,V2,V3){
  if(document.form.V1.checked) {
    window.alert("test");
  } else if(document.form.V2.checked) {
    window.alert("test");
  } else if(document.form.V3.checked) {
    window.alert("test");
  } else {
    window.alert("Pick something!!");
  }
}// -->
</script>


</form>

Code (markup):

thanks again

 

When radio buttons have the same name to group them together javascript treats them as an array not individual elements. So your function needs to change to:

function decision(V1,V2,V3){
if(document.form.R1[0].checked) {
window.alert("test");
} else if(document.form.R1[1].checked) {
window.alert("test");
} else if(document.form.R1[2].checked) {
window.alert("test");
} else {
window.alert("Pick something!!");
}
}


The parameters you are passing to the function are not used.

 

thansk for your advice i have changed the code to what you said but i am still getting errors. This is the page
http://homepage.ntlworld.com/fraser_d/buy-scottish-photos.htm
i just cannot work it out any ideas of what else im doing wrong?
thanks

 

This line is incorrect:

<img border="0" src="x-click-but23.gif" align="center" width="68" height="23" onclick="decision(<V1>,<V2>,<V3>">

The closing bracket on the decision function call is missing. I also do not see what the <V1> etc parameters are. Change the above line to:

<img border="0" src="x-click-but23.gif" align="center" width="68" height="23" onclick="decision()">

and change thew function header to:

function decision() {

That will remove your javascript errors.

 

thansk for your advice spot on! nearly there just a couple more bugs