text: 
   function triangle()
   {
    var side = [side1,side2,side3];
  
     var side1= parseInt(document.getElementById('sidea').value);
     var side2= parseInt(document.getElementById('sideb').value);
     var side3= parseInt(document.getElementById('sidec').value);
  
    if((side1+side2>side3) && (side1+side3>side2) && (side2+side3>side1)){
  
      alert("This can be a triangle");
  
     if((side1 === side2) && (side2 === side3) && (side1 === side3))
     {
      alert("This triangle is Equilateral.");
     }
     else if((side1 === side2) || (side2 === side3) || (side1 === side3))
     {
       alert("This triangle is Isoscele.");
     }
     else if((side1!==side2) || (side2!==side3) || (side1!==side3) && (side2!==0))
     {
      alert("This triangle is Scalene.");
     }
    }
     else
     {
       alert("There is no any existence of a triangle.");
     }
      };