Untitled

<html>
<head>
<title>Test</title>
<script language="javascript">
function chan(){
 if(document.test.main.checked==true){
  document.test.first.disabled=true;
  document.test.second.disabled=true;
  document.test.third.disabled=true;
  }
 else{
  document.test.first.disabled=false;
  document.test.second.disabled=false;
  document.test.third.disabled=false;
  }  
 }
</script>
</head>

<body>
<form name="test">
<input name="main" type="checkbox" onChange="chan()"> Вкл/Выкл<br>
<input name="first" type="text"><br>
<input name="second" type="radio"><br>
<select name="third">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
</select>
</form>
</body>
</html>