javascript验证完全方法具体实现

var certCardValid = function(id){
        var arrVerifyCode = [1,0,"x",9,8,7,6,5,4,3,2];
        var wi = [7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2];
        var Checker = [1,9,8,7,6,5,4,3,2,1,1];
        var msg = "";
        if(id.length != 15 && id.length != 18) {
            Ext.MessageBox.alert("信息提示","号共有15位或18位。");
            return false;
        }
        
        var ai = id.length == 18 ?  id.substring(0,17) : id.slice(0,6) + "19" + id.slice(6,16);
 
 
        if (!/^/d+$/.test(ai)) {
            Ext.MessageBox.alert("信息提示","除最后一位外，必须为数字。");
            return false;
        } 
 
 
        var yyyy = ai.slice(6,10);
        var mm = ai.slice(10,12)-1; 
        var dd = ai.slice(12,14);
        var d = new Date(yyyy,mm,dd);
        var now = new Date();
        var year = d.getFullYear();
        var mon = d.getMonth(); 
        var day = d.getDate();
 
 
        if (year != yyyy || mon != mm || day != dd) {
            Ext.MessageBox.alert("信息提示","无效。");
            return false;
        }
 
 
        for(var i = 0,ret = 0; i < 17; i++){
            ret += ai.charAt(i) * wi[i];
        }
        
        ai += arrVerifyCode[ret %= 11];
        ai = ai.toUpperCase();
 
 
        if(id.length == 18 && id != ai){
            Ext.MessageBox.alert("信息提示","无效。");
            return false;
        }
        return true;
    };