value属性应该包含在选中复选框时将发送到服务器的值。如果未选中复选框，则不会发送任何内容。

<label for="checkboxField">A checkbox field</label> 
<input type="checkbox" name="checkboxField" id="checkboxField" value="yes" /> 
您可以通过向输入标记添加checked =“checked"属性来预先选择复选框:
<input type="checkbox" checked="checked" ... />. 
通过创建具有相同name属性的多个复选框字段，您可以允许用户选择同一字段的多个值。
以下脚本用于index.htm。 它有几个复选框。
<form action ="index.php">
  <li><input type ="checkbox" name ="chkFries" value ="11.00">Fries</li>
  <li><input type ="checkbox" name ="chkSoda"  value ="12.85">Soda</li>
  <li><input type ="checkbox" name ="chkShake" value ="1.30">Shake</li>
  <li><input type ="checkbox" name ="chkKetchup" value =".05">Ketchup</li>
<input type ="submit">
</form>
</body>
</html>
以下代码用于index.php，它接受来自复选框的值。
print "chkFries:" .  $chkFries . "<br/>";
print "chkSoda:" $chkSoda . "<br/>";
print "chkShake:" . $chkShake . "<br/>";
print "chkKetchup" . $chkKetchup . "<br/>";
$total = 0;
if (!empty($chkFries)){
  print ("You chose Fries <br>");
  $total = $total + $chkFries;
if (!empty($chkSoda)){
  print ("You chose Soda <br>");
  $total = $total + $chkSoda;
if (!empty($chkShake)){
  print ("You chose Shake <br>");
  $total = $total + $chkShake;
if (!empty($chkKetchup)){
  print ("You chose Ketchup <br>");
  $total = $total + $chkKetchup;
print "The total cost is \$$total";