C# Calculation not correct -

when run code, doesn't calculate , doesn't show calculations. wondering if variables or else wrong or maybe in wrong place.

using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.threading.tasks; using system.windows.forms;  namespace question_3_retail_price_calculator {     public partial class form1 : form     {         public form1()         {             initializecomponent();         }          private void button1_click(object sender, eventargs e)         {             decimal costprice = 0;             decimal markupratea = 0.19m;             decimal markuprateb = 0.14m;             decimal markupratec = 0.12m;             decimal markuprate = 0m;             decimal markuptotal = 0;             decimal totalcost = 0;              // add items listbox 1             listbox1.items.add("markup rate =");             listbox1.items.add("markup total =");             listbox1.items.add("total cost =");              try             {                 // read cost price user                 costprice = decimal.parse(textbox1.text);              }            catch (system.exception excep )              {                  messagebox.show(excep.message);              }                  if (costprice <= 50)                 {                     // calculate value of  product                      costprice = (costprice / 100) * markupratea;                   }                 else if (costprice >= 50 && costprice < 100)                 {                     //  calculate value of product                     costprice = (costprice / 100) * markuprateb;                 }                 else if (costprice < 100)                 {                     // calculate value of product                     costprice = (costprice / 100) * markupratec;                 }                 else if (markuprate == markuptotal)                 {                     // calculate total monetary amount                     markuptotal = costprice * markuprate;                 }                 else                 {                     // calculate total cost  of product                     totalcost = costprice + markuptotal;                 }                 // output total cost                 messagebox.show("total cost is: €"  + totalcost);             }     } } 

need figuring out! in advance!

you're setting total cost in last else condition executed if other if-else conditions not executed. why code isn't working expect.

even if enter value >100, result never assigned totalcost. because execution enters part of code

         else if (markuprate == markuptotal)         {             // calculate total monetary amount             markuptotal = costprice * markuprate;         } 

and jumps directly message.show(..) line.