function ismail(mail){ 
        return(new RegExp(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/).test(mail)); 
      } 
 function checkLong(str,l){
     if(str.length>l){
       return true;
     }
     else{
     return false;
     }
  }
  
  function checkpassword(str){
    if(/[^0-9a-zA-Z]/g.test(this.value)){
      return true;
    }
  }
  //check 2009-06-06
  function strDateTime(str) 
      { 
         var r = str.match(/^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2})$/); 
         if(r==null)return false; 
         var d= new Date(r[1], r[3]-1, r[4]); 
         return (d.getFullYear()==r[1]&&(d.getMonth()+1)==r[3]&&d.getDate()==r[4]); 
      } 
   //check 2003-12-05 13:04:06
  function strDateTime(str) 
      { 
        var reg = /^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2}) (\d{1,2}):(\d{1,2}):(\d{1,2})$/; 
        var r = str.match(reg); 
        if(r==null)return false; 
        var d= new Date(r[1], r[3]-1,r[4],r[5],r[6],r[7]); 
        return (d.getFullYear()==r[1]&&(d.getMonth()+1)==r[3]&&d.getDate()==r[4]&&d.getHours()==r[5]&&d.getMinutes()==r[6]&&d.getSeconds()==r[7]); 
  }
  //check A-z and number
  function checkcode(svalue){
  var zhengshu = /^(\s)*[A-Za-z0-9]*(\s)*$/;/*/^[A-Za-z0-9]+$;/*/
  if(zhengshu.test(svalue)){
      return true;
   }else{
     return false;
  }
}