text: var calculater=function(){
      var inputValue=document.getElementById("inputNumber").value;
      
      var sum=0;
      
       if( inputValue<=0  ){
              alert("end value should larger than 0");
        }else{ 
                for(var i=0 ; i<=inputValue   ; i++ ){
                   sum+=i;
                }
            document.getElementById("sumResult").innerHTML=sum;
              } 
      }
      
  var clickMe=function(){
      calculater();
  }
  