Mobile Application Development in ASP.NET

using System;
using System.Web.Mobile;
using System.Web.UI.MobileControls;
using System.Text;
using Microsoft.VisualBasic;

namespace STL.Web.Mobile.UI
{
    public partial class Loan_RepaymentCalculator : System.Web.UI.MobileControls.MobilePage
    {
        #region Event

        protected void Page_Load(object sender, EventArgs e)
        {
            Initialize();
        }

        protected void cmdRepayment_Click(object sender, EventArgs e)
        {
            if (!Page.IsValid) return;
            try
            {
                Double dblPrincipal = double.Parse(this.PrincipalAmount.Text);
                Double dblApr = double.Parse(this.Rate.Text);
                Double dblMonthlyInterest = (Double)(dblApr / (12 * 100));
                Int64 intTermInMonths = Int64.Parse(this.Term.Text) * 12;
                Double dblMonthlyPayment;

                dblMonthlyPayment = Microsoft.VisualBasic.Financial.Pmt(dblMonthlyInterest, intTermInMonths, -dblPrincipal, 0, Microsoft.VisualBasic.DueDate.BegOfPeriod);

                this.ActiveForm = this.frmResult;

                StringBuilder sbDetailsSpec = new StringBuilder("");
                sbDetailsSpec.Append(String.Format("{0} @ {1}% for {2} years <br /> Payment: ", dblPrincipal.ToString("C0"), dblApr.ToString(), this.Term.Text));
                sbDetailsSpec.Append("<b>" + dblMonthlyPayment.ToString("C") + "</b>");
                this.tvLoanDetails.Text = sbDetailsSpec.ToString();
            }
            catch
            {
                this.ActiveForm = frmError;
            }
        }

        protected void cmdBack_Click(object sender, EventArgs e)
        {
            this.ActiveForm = this.frmInput;
        }

        #endregion Event

        #region Method

        private void Initialize()
        {
            this.frmInput.Title = UIConstant.TITLE_BAR;
            this.frmResult.Title = UIConstant.TITLE_BAR;
            this.frmError.Title = UIConstant.TITLE_BAR;

            this.lblHeading.Text = UIConstant.PAGE_TITLE;
            this.lblHeadingResult.Text = UIConstant.PAGE_TITLE;
            this.lblHeadingError.Text = UIConstant.PAGE_TITLE;
        }

        #endregion Method
    }
}