Binary to decimal & vice versa now works

num-converter/WebForm1.aspx.cs

@@ -16,7 +16,31 @@ namespace num_converter
 
         protected void btnConvert_Click(object sender, EventArgs e)
         {
+            String Result = string.Empty;
+            int Remainder;
+            int DecimalNum;
+            int BinaryNum;
+            int OctalNum;
+            int Base1 = 1;
             
+            if (ddlSourcePosNum.SelectedIndex == 1 && ddlTargetPosNum.SelectedIndex == 2)
+            {
+                DecimalNum = Convert.ToInt32(txtInput.Text);
+                while (DecimalNum > 0)
+                {
+                    Remainder = DecimalNum % 2;
+                    DecimalNum /= 2;
+                    Result = Remainder.ToString() + Result;
+                }
+                lblResult.Text = Result;
+            }
+            if (ddlSourcePosNum.SelectedIndex == 2 && ddlTargetPosNum.SelectedIndex == 1)
+            {
+                BinaryNum = Convert.ToInt32(txtInput.Text, 2);
+                Result = BinaryNum.ToString();
+
+                lblResult.Text = Result;
+            }
         }
 
         protected void btnClear_Click(object sender, EventArgs e)