<form action='suche.php' method='post'>

<input type='radio' name='suchart' value='1'>
<input type='text' name='id'>


<input type='radio' name='suchart' value='2'>
<select name='liste' size='10'>
<option value='1'>LAALAAALAAAA</option>
</select>


<input type='radio' name='suchart' value='3'>
Name: <input type='text' name='name' size='20'>


<input type='submit' value='Suchen'></form>

<script language="JavaScript">
function setradio(art) {
  document.forms[0].suchart[art].checked = true;
}
</script>

<form action='suche.php' method='post'>

<input type='radio' name='suchart' value='1'>
<input type='text' name='id' onChange="setradio(0);">


<input type='radio' name='suchart' value='2'>
<select name='liste' size='10' onChange="setradio(1);">
<option value='1' >LAALAAALAAAA</option>
</select>


<input type='radio' name='suchart' value='3'>
Name: <input type='text' name='name' size='20' onChange="setradio(2);">


<input type='submit' value='Suchen'></form>