hi,
i encounter some problem to validate the empty radio button and check box with javascript and html for compulsory form.
when i not select the radio button and check box,it will pop up the messages. but when i select the radio button and check box which is required compulsory to select,i click the submit.It cant go to next page.

hope anyone can help me to solve the problem.thanks in advance.
HTML Code:
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Survey Form</title>
<style>
<!--
.txt_title {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 14px;
	font-weight: bold;
	color: #000000;
}
.txt_redstar {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 14px;
	color: #FF0000;
}
.txt_body {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 14px;
	color: #000000;
}
-->
</style>
</head>

<body>
<script type="text/javascript" src="validation.js"></script>   
         <form method="post" action="detailsForm.html" name="form1" >
<table align="center" border="0" cellpadding="10" cellspacing="10" class="table">
    <tr>
      <td height="80"><div align="left" class="txt_title">Thank you for taking time to complete this survey  for us.</div>
        <div align="left" class="txt_title">In appreciation of your time and effort, the first 100 respondents to this survey will receive S$5 NTUC voucher from us.</div></td></tr>
        <td height="20"><div align="left" class="txt_redstar">*indicates compulsory questions/fields</div></td></tr>
         
	<tr>
		<td height="40"><div align="left" class="txt_body">1.	Have you used mouthwash in the past 3 months?<span class="txt_redstar">*</span><br />
        <input type="radio" name="radio" id="radio" value="yes">Yes<br>
  <input type="radio" name="radio" id="radio" value="no">No<br></div></td>
	</tr>
 
    <tr>
		<td height="40"><div align="left" class="txt_body">2.	Have you used mouthwash in the past 1 month?<br />
        <input type="radio" name="radio1" id="radio1" value="yes1">Yes<br>
  <input type="radio" name="radio1" id="radio1" value="no1">No<br></div></td>
    </tr>
    <tr>
       <td height="40"><div align="left" class="txt_body">3. (For those who have used mouthwash in the past 3 months but not in the past 1 month)<br />
          Please state the reason why you stopped using mouthwash in the past 1 month?<br />
           <input type="checkbox" name="11" id="11" value="1">My oral care problems are cured/resolved<br />
           <input type="checkbox" name="22" id="22" value="2">Mouthwash is too expensive<br />
           <input type="checkbox" name="33" id="33" value="3">Have doubt about mouthwash safety<br />
           <input type="checkbox" name="44" id="c44" value="4">Have doubt about mouthwash efficacy<br />
          </div></td>
	</tr>
	<tr>
	  <td height="40"><div align="left" class="txt_body">4. What was the content of the advertising? ( tick all that apply)<span class="txt_redstar">*</span><br />
           <input type="checkbox" name="1" id="1" value="1">Mouthwash kills germ that caused bad breath, plaque and  gingivitis<br />
           <input type="checkbox" name="2" id="2" value="2">Mouthwash gives you fresher breath, healthier teeth and gum<br />
           <input type="checkbox" name="3" id="3" value="3">Alcohol containing mouthwash has a risk (related to oral  cancer)<br />
           <input type="checkbox" name="4" id="4" value="4">Alcohol free mouthwash is better<br />
           <input type="checkbox" name="5" id="5" value="5">Mouthwash with alcohol is more efficacious<br />
           <input type="checkbox" name="6" id="6" value="6">Others <input name="others" type="text" value="" size="15"><br />
          </div></td>
	</tr>
    <tr>
        <td><input type="button" name="submit" value="Submit"onClick="javascript:validate();"></td>
    </tr>
</table>
</form>
</body>
below is validation of javascript
// JavaScript Document
function validate(){
if (document.getElementById("radio").checked==""){
alert("You have not answered all compulsory questions; please review and answer the questions marked with *");
return false;
}
else if((document.getElementById("1").checked=="")&&(do cument.getElementById("2").checked=="")&&(document .getElementById("3").checked=="")
&&(document.getElementById("4").checked=="")&&(doc ument.getElementById("5").checked=="")&&(document. getElementById("6").checked=="")){

alert("You have not answered all compulsory questions; please review and answer the questions marked with *");
return false;
}


document.form1.submit();
}
HTML Code:
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Details Form</title>
<style>
<!--
.txt_title {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 14px;
	font-weight: bold;
	color: #000000;
}

.txt_body {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 14px;
	color: #000000;
}
-->
</style>
</head>

<body>
<table align="center" border="0" cellpadding="10" cellspacing="10" class="table">
<tr>
      <td width="261" height="80"><div align="left" class="txt_body">Please enter your information below, so that we can contact you if you qualify for the voucher (information is collected securely for this sole purpose).</div></td></tr>
</table>
   <script type="text/javascript" src="validation1.js"></script>   
<form method="post" action="success.html" name="form1" >
<table align="center" border="0" cellpadding="10" cellspacing="10" class="table">
<tr>
		<td><label>Full Name</label></td><td width="133">
                <input type="text" name="name" id="name" value=""></td>
	</tr>
	<tr>
		<td><label>Email Address</label></td><td>
                <input type="text" name="email" id="email" value=""></td>
	</tr>
    <tr>
		<td><label>Mobile No</label></td><td>
                <input type="text" name="mobile" id="mobile" value=""></td>
	</tr>
    <tr>
		<td><label>Address</label></td><td>
                <input type="text" name="address" id="address" value=""></td>
	</tr>
    <tr>
		<td><label>Postal Code</label></td><td>
                <input type="text" name="postal" id="postal" value=""></td>
	</tr>
    <tr>
        <td><input type="button" name="Submit" value="Submit" onClick="javascript:validate();"></td>
    </tr>
</table>
</form>
</body>