Champs select (grisé / dégrisé) si checkbox cochée

Bonjour un champs select que je veux le désactivé lorsque la case à coché est activer , le contraire .. .

Code:

1
2
3
4
5
6
7
8
9
10
11
<script language="javascript">
 
function trmodif()
 
{
if(document.getElementById('jform_varBoolTierce').checked)
 document.getElementById('jform_varListCollision').disabled=true;
 else
  document.getElementById('jform_varListCollision').disabled=false;
}
</script>

Code PHP

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
<li id="calc-varBoolTierce" class="calc-input">
<label id="jform_varBoolTierce-lbl" for="jform_varBoolTierce" class=""><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARBOOLTIERCE"); ?></label>
<input type="checkbox" name="jform[varBoolTierce]" id="jform_varBoolTierce" onclick="javascript:trmodif()" value="1" class=""<?php if($varBoolTierce) echo " checked=\"checked\"" ?> />
</li>
 
<li id="calc-varListCollision" class="calc-input">
<label id="jform_varListCollision-lbl" for="jform_varListCollision" class=""><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTCOLLISION"); ?></label>
<select id="jform_varListCollision" onchange="javascript:modif()" name="jform[varListCollision]" class="">
	<option <?php if($varListCollision=="1") echo "selected=\"selected\"" ?> value="1"><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTBDG_1"); ?></option>
	<option <?php if($varListCollision=="2") echo "selected=\"selected\"" ?> value="2"><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTCOLLISION_2"); ?></option>
	<option <?php if($varListCollision=="3") echo "selected=\"selected\"" ?> value="3"><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTBDG_5"); ?></option>
	<option <?php if($varListCollision=="4") echo "selected=\"selected\"" ?> value="4"><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTCOLLISION_4"); ?></option>
	<option <?php if($varListCollision=="5") echo "selected=\"selected\"" ?> value="5"><?php echo JText::_("MOD_MEMEDAYS_CONVERTER_VARLISTCOLLISION_5"); ?></option>
</select>
 
</li>

Merci d'avance