JavaWeb学习（三）对输入的限制 , 复选框的使用

对输入的限制 

<form name = "form1" action = "" method="post" onsubmit="return check()" >

</form>

<script type = "text/javascript">
   function check()
{
   var name = document.form1.name.value;
   .........
   //非空
   if(name == ''){
   alert('姓名为空')
   return false;
}
 ..........
   //判断负数,小数
  if( (document.theForm.shu_mu.value.indexOf( "-" ) == 0|| !(document.theForm.shu_mu.value.indexOf(".") ) 

    //身份证
function check_word()
{
    var arr = ["a" ...."Z"];
    for(var i = 0 ; i < arr.length ; i++)
   {
 for(var j = 0 ; j < str.length ; j++)
{

     if( arr[i] == str.charAt(j) )

     if( arr[i] == "X" && j == 18)

       return false;

   }

return true;

}

 

二. 复选框输入

JSP

<input type="checkbox" name="a1" value="" />
<input type="checkbox" name="a2" value="" />
 ...............

Servlet

String a1 = null;
String a2 = null;
...
if (request.getParameter("a1") != null)
   a1 = request.getParameter("a1") + ''; 
else
 a1 = "" ;

String all = a1 + a2 +......;