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 function checkDate()
   {
       startDate = document.getElementById("exportPayIndex:beginSubDate").value; 
                    endDate = document.getElementById("exportPayIndex:endSubDate").value;      
        if(startDate == "" && endDate != "")
        {  
                        alert("开始日期不能为空!");
                        return false;
        }
        if(endDate!= ""&& endDate == "")
        {
             alert("结束日期不能为空!");
              return false;
        }
                   
         if (startDate != "")
        {
                       if (endDate != "")
                       {
                           startDate =  changeDate(startDate);
                           endDate = changeDate(endDate);
                           if (startDate > endDate)
                           {
                              alert("结束日期应该大于或等于开始日期!");
                              return false;
                           }
                        }
          }                   
  
   }
    //时间转换函数
                   function changeDate(temp)
                   {
                       arrdate=temp.split(‘-‘);
                       if(arrdate.length < 2)
                       {
                       return  temp;
                       }
                       else
                       {
                       if(arrdate[1].length==1)
                       {
                       arrdate[1]="0"+arrdate[1];
                       }
                       if(arrdate[2].length==1)
                       {
                       arrdate[2]="0"+arrdate[2];
                       }
                       return    arrdate.join("-");
                       }
                    }