客户端脚本验证码总结一

            function Jtrim(str)  //去空隔函数

            {

                    var i = 0;
                    var len = str.length;
                    if ( str == "" ) return( str );
                    j = len -1;
                    flagbegin = true;
                    flagend = true;
                    while ( flagbegin == true && i< len)
                    {
                       if ( str.charAt(i) == " " )
                            {
                              i=i+1;
                              flagbegin=true;
                            }
                            else
                            {
                                    flagbegin=false;
                            }
                    }

                    while  (flagend== true && j>=0)
                    {
                        if (str.charAt(j)==" ")
                            {
                                    j=j-1;
                                    flagend=true;
                            }
                            else
                            {
                                    flagend=false;
                            }
                    }

                    if ( i > j ) return ("")

                    trimstr = str.substring(i,j+1);
                    return trimstr;
            }

                    function isNumber(s) //数字判断函数
                    {
                            var digits = "0123456789";
                            var i = 0;
                            var sLength = s.length;

                            while ((i < sLength))
                            {
                                    var c = s.charAt(i);
                                    if (digits.indexOf(c) == -1) return false;
                                    i++;
                            }

                            return true;
                    }
            function isemail (s)//验证E-MAIL格式函数
            {
                   
                    if (s.length > 100)
                    {
                            window.alert("email地址长度不能超过100位!");
                            return false;
                    }

                     var regu =
            "^(([0-9a-zA-Z]+)|([0-9a-zA-Z]+[_.0-9a-zA-Z-]*[0-9a-zA-Z]+))@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2}|net|NET|com|COM|gov|GOV|mil|MIL|org|ORG|edu|EDU|int|INT)$"
                     var re = new RegExp(regu);
                     if (s.search(re) != -1) {
                           return true;
                     } else {
                           window.alert ("请输入有效合法的E-mail地址 ！")
                           return false;
                     }
            }
            //判断是否中文函数
            function ischinese(s){
            var ret=true;
            for(var i=0;i<s.length;i++)
            ret=ret && (s.charCodeAt(i)>=10000);
            return ret;
            }
            //--------------------------------------------------------------------------------
            function ismit()//判断radio是否没有选择函数
            {
                    var count=0;
                    for (ii=0;ii<myform.elements.length;ii++)
                    {
                            if (myform.elements[ii].type=="radio" &&
            myform.elements[ii].checked==true)
                            {
                                            count++;
                            }
                    }
                     
                     if (Jtrim(document.myform.user_name.value)=='') {
                            window.alert ("请输入您的队员名 ！")
                            myform.user_name.focus();
                            return false;
                    }
                   if(ischinese(document.myform.user_name.value)){
                   window.alert("请输入英文队员名")
                   myform.user_name.focus();
                            return false;
            }
                   
                }
                  if (Jtrim(myform.user_pass1.value)=="" ||
            myform.user_pass1.value.length < 4)
                 {
                     alert("您的密码不能为空且不能少于4位数！");
                     myform.user_pass1.focus();
                     myform.user_pass1.select();
                     return false;
                 }
                 if (Jtrim(myform.user_pass2.value)=="" ||
            myform.user_pass2.value.length < 4)
                 {
                     alert("您的确认密码不能为空且不能少于4位数！");
                     myform.user_pass2.focus();
                     myform.user_pass2.select();
                     return false;
                 }
                 if (myform.user_pass1.value!=myform.user_pass2.value)
                 {
                             alert("您两次输入的密码不相同，请重新输入！");
                             myform.user_pass1.value="";
                             myform.user_pass2.value="";
                             myform.user_pass2.focus();
                             return false;
                 }
             
                    if (!isNumber(document.myform.user_qq.value))
                    {
                      window.alert ("QQ号码应该是数字,请重新输入!");
                      myform.user_qq.focus();
                      myform.user_qq.value='';
                     return false;
                 }
                    if (Jtrim(document.myform.user_email.value)==''){
                    window.alert("请填写您经常使用的一个邮箱！");
                    myform.user_email.focus();
                    return false;
                 }
                 if (!isemail(document.myform.user_email.value))
                 {
                     myform.user_email.focus();
                     return false;
                 }
                 if (myform.user_question.value==0)
                 {
                     alert("请选择一个密码提示问题");
                     myform.user_question.focus();
                     return false;
                 }
                
                return true;
            }