Hex to Oct Vice Versa Converter Using c#

/*First u must create a Ui*/


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
  public partial class Form1 : Form
  {
      public Form1()
      {
        InitializeComponent();
      }

      private void button1_Click(object sender, EventArgs e)
      {
       int x, flag = 0;
       for (x = 0; x <> 97 && textBox1.Text[x]
 <> 64 && textBox1.Text[x] < flag =" 1;" 
flag ="=" text = "" val =" 0," power =" 
(textBox1.TextLength" str = "" str2 = "" i =" 0;"
 num =" val;" rem =" num" num =" num" rem ="=" 
rem ="=" rem ="=" rem ="=" rem ="=" rem ="=" i =" 
str.Length">= 0; i--)
              {
                  str2 += str[i];
              }
              if (textBox1.Text == "0")
                  textBox2.Text = "0";

              textBox2.Text = textBox2.Text + str2;
          }
          else
          {
MessageBox.Show("Value should not have digits like 8, 9 or any alphabet!");
              textBox1.Text = "";
          }

      }

      private void button2_Click(object sender, EventArgs e)
      {
          textBox4.Text = "";
          int val = 0, power = (textBox3.TextLength - 1), i;
          int num, rem;
          String str = "", str2 = "";


     for (i = 0; i < num =" val;" rem =" (int)num" num =" 
(int)num" i =" str.Length">= 0; i--)
          {
              str2 += str[i];
          }

    textBox4.Text = textBox4.Text + str2;  
      }

   private void Form1_Load(object sender, EventArgs e)
      {

      }
  }
}