// JScript source code

function DateAdd(datepart, number, date) {    
  var d = new Date(date);     
   switch (datepart) {         // millisecond
            case "ms":            
            return new Date(Date.parse(d) + (number));         
            // second         
            case "s":         
            case "ss":            
            return new Date(Date.parse(d) + (number*1000));         
            // minute         
            case "n":         
            case "mi":            
            return new Date(Date.parse(d) + (number*1000*60));         
            // hour         
            case "hh":            
            return new Date(Date.parse(d) + (number*1000*60*60));         
            // day        
             case "d":         
             case "dd":            
             return new Date(Date.parse(d) + (number*1000*60*60*24));         
             // week         
             case "wk":         
             case "ww":            
             return new Date(Date.parse(d) + (number*1000*60*60*24*7));         
             // month         
             case "m":         
             case "mm":            
             return new Date(d.getFullYear(),d.getMonth()+number,d.getDate(),   d.getHours(), d.getMinutes(),  d.getSeconds());  
              // quarter         
              case "q":         
              case "qq":            
              return new Date(               d.getFullYear(),               d.getMonth()+number*3,               d.getDate(),               d.getHours(),               d.getMinutes(),               d.getSeconds());         
              // year         
              case "yy":         
              case "yyyy":            
              return new Date(               d.getFullYear()+number,               d.getMonth(),               d.getDate(),               d.getHours(),               d.getMinutes(),               d.getSeconds());     
               }  
                
              }