常用的javascript

上传的file为空：
    function fnsave(){
      if(document.forms[0].file.value.length==0) {
        alert("提示：请选择要上传的文件！");
        document.forms[0].file.focus();
        return false;
      }
    }
上传的格式验证：
     var fileName = document.forms[0].file.value;
      if(fileName.indexOf('.xls') == -1){
      alert("警告：上传的文件必须为excel文件！");
      document.forms[0].file.focus();
      return false;
      }
提交的action为：
    document.forms[0].action="excelInAction.do?op=doExcelIn";
Form的提交：
      document.forms[0].submit();
设置为空：
    document.forms[0].file.value = "";
表单验证：
思路：首先获得到值
    function fnquery(){
     var qymc=document.form1.vchr_qymc.value;
     var zch=document.form1.vchr_zch.value;
     if(Trim(qymc)==""&&Trim(zch)==""){
      alert("至少有一个查询条件");
      return false;
     }
      form1.action="baqyjyAction.do?op=qycxjg";
      form1.submit();

    function Trim(str) {
      blnbeginflag=true
      blnendflag=true
     for (i=0;i<str.length;i++) {
      if ((str.indexOf(" ")==0) && blnbeginflag){
       intlen=str.length
       str=str.substring(1,intlen)
       i--
      }else{
       blnbeginflag=false
      }
      if ((str.lastIndexOf(" ")==(str.length-1)) && blnendflag) {
         str=str.substring(0,str.length-1)
      }else{
        blnendflag=false
      }
     }
      return str
    }
表单清空：
    function fnclear(){
     document.form1.vchr_qymc.value="";
     document.form1.vchr_zch.value="";
    }
弹出窗口：
这里是传递一个企业id：
    function fnview(qyid){

    url = "xjqyxxAction.do?op=ckqyjbxx&qyid="+qyid;
    openwin(url,"企业信息查看");
    }
跳到另个页面action：
    function fnadd(){
      document.location.href="xjqyxxAction.do?op=create&qyid=";
    }
返回：
    function fncancel(){
      location="baqyjyAction.do?op=view";
    }
javascript存放java代码：打开一个窗口，可以控制各种属性window.open
    function fnload(){
    <%
      boolean isopen=request.getSession().getAttribute("ba.qyid")!=null;
      System.out.println("企业ID："+(String)request.getSession().getAttribute("ba.qyid"));
      if(isopen){
    %>  //新建特殊信息录入
     window.open("xjqyxxAction.do?op=tsxx","newtsxx","left=300,top=300,height=150,width=500,fullscreen=2,status=no,toolbar=no,menubar=no,location=no");
    <%
     }
    %>
    }
关闭按钮：
    function fanhui(){
    self.close();
       }
在body里加iframe：可以控制iframe的属性
     <iframe id="rzframe" name="rzframe" align="button" width="100%"
    height="30%" scrolling="yes" frameborder="0"
    src="rzrdjgAction.do?op=list&qyid=<%=request.getParameter("qyid") %>&rzview='001me>
长度范围判断：
      if(vchr_qymc!=""&&strlength(vchr_qymc)>100){
    alert("企业名称输入超出范围！");
    return false;
      }
      function strlength(str){
     var l=str.length;
     var n=l
     for (var i=0;i<l;i++)
     {
      if (str.charCodeAt(i)<0||str.charCodeAt(i)>255) n++
     }
     return n
    }
判断是否是数字组成：
    var szpd="0123456789";
    if(vchr_dh!=""){
     for(i;i<vchr_dh.length;i++){
        var dh=vchr_dh.charAt(i);
         if (szpd.indexOf(dh)==-1){
        alert("电话号码是数字组成的");
        document.forms(0).vchr_dh.value="";
        return false;
         }  
     }
    }
ajax实现：
    var req;
    function getReq(){
      if (window.ActiveXObject){
       req = new ActiveXObject("Microsoft.XMLHTTP");
        } else if (window.XMLHttpRequest) {
       req = new XMLHttpRequest();
        }
        return req;
     }
    function selctdsdm() {
       var  ssdm  =  document.all.chr_ssdm.value; 
      var url = "xjqyxxAction.do?op=selctdsdm&ssdm="+ssdm;
      var req = getReq();
        if(req){
        req.open("GET",url, true);
        req.onreadystatechange = dscomplete;
        req.send(null);
        }
     }
    function dscomplete(){
       if (req.readyState == 4) {
      if (req.status == 200) {
        document.getElementById("dsselect").innerHTML = req.responseXML.getElementsByTagName("select1")[0].firstChild.data;
        document.getElementById("qxselect").innerHTML = req.responseXML.getElementsByTagName("select2")[0].firstChild.data;
      } else {
        alert('There was a problem with the request.');
      }
       }
     }
    function selctqxdm() {
       var  dsdm  =  document.all.chr_dsdm.value; 
      var url = "xjqyxxAction.do?op=selctqxdm&dsdm="+dsdm;
      var req = getReq();
        if(req){
        req.open("GET",url, true);
        req.onreadystatechange = qxcomplete;
        req.send(null);
        }
     }
    function qxcomplete(){
       if (req.readyState == 4) {
      if (req.status == 200) {
        document.getElementById("qxselect").innerHTML = req.responseText;
      } else {
        alert('There was a problem with the request.');
      }
       }
     } //启动的时候浏览器加载selectdsdm
Email格式验证：
    //验证E-mail的格式
    function checkMailFormat(str){
       Str = ""+str;
       RegularExp = /[a-z0-9]*@[a-z0-9]*/.[a-z0-9]+/gi
       if (RegularExp.test(Str)){
        return true;
       }else{
        alert("电子信箱格式不对！");
        return false;
       }
    }