How to reset the minsupp..?

Question

how to reset the minimum support that the user enter in the RTB? when user want to change the minimum support, they can straight away change from the minimum support RTB and the program can detect and change also..
??
here is my coding:

           MinSupp.Clear();

           double minsupp = Double.Parse(MinSupp.Text);

           double totalsupp = 0.0;

           foreach (var r in p)

           {

               totalsupp += (double)dict1[r];

           }

 

           SingleItemValue.Clear();

           foreach (var h in p)

           {

               double supp = (double)dict1[h];

               double perc = supp / totalsupp * 100.00;

               if (perc >= minsupp)

               {

                   SingleItemValue.AppendText(h + ":" + dict1[h] + "\r\n");

                   hs1.Add(h);

               }

           }