Combobox connecting problem!

[invinci]

Hi, i am new to Visual C++ and facing problem in integrating two combo boxes.

Here is what i need:

Combobox1 - Material of Plate:
Choice: Metal or Plastic

Combobox2 - Thickness of Plate:
Choice: if Metal in Combobox1: 2,3,4,5,6
Choice: if Plastic in Combobox1: 8,10,15

I am unable to solve the problem, can any one help me out with the this!...any help is highly appreciated...!

The code is as follows:

#pragma once

namespace Program {

    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
    using namespace System::Windows::Forms;
    using namespace System::Data;
    using namespace System::Drawing;

    /// <summary>
    /// Summary for Form1
    ///
    /// WARNING: If you change the name of this class, you will need to change the
    ///          'Resource File Name' property for the managed resource compiler tool
    ///          associated with all .resx files this class depends on.  Otherwise,
    ///          the designers will not be able to interact properly with localized
    ///          resources associated with this form.
    /// </summary>
    public ref class Form1 : public System::Windows::Forms::Form
    {
    public:
        Form1(void)
        {
            InitializeComponent();
            //
            //TODO: Add the constructor code here
            //
        }

    protected:
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        ~Form1()
        {
            if (components)
            {
                delete components;
            }
        }
    private: System::Windows::Forms::ComboBox^  comboBox1;
    protected: 
    private: System::Windows::Forms::ComboBox^  comboBox2;
    private: System::Windows::Forms::Label^  label1;
    private: System::Windows::Forms::Label^  label2;
    private: System::Windows::Forms::Label^  label4;

    private:
        /// <summary>
        /// Required designer variable.
        /// </summary>
        System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        void InitializeComponent(void)
        {
            this->comboBox1 = (gcnew System::Windows::Forms::ComboBox());
            this->comboBox2 = (gcnew System::Windows::Forms::ComboBox());
            this->label1 = (gcnew System::Windows::Forms::Label());
            this->label2 = (gcnew System::Windows::Forms::Label());
            this->label4 = (gcnew System::Windows::Forms::Label());
            this->SuspendLayout();
            // 
            // comboBox1
            // 
            this->comboBox1->FormattingEnabled = true;
            this->comboBox1->Items->AddRange(gcnew cli::array< System::Object^  >(2) {L"Metal", L"Plastic"});
            this->comboBox1->Location = System::Drawing::Point(142, 34);
            this->comboBox1->Name = L"comboBox1";
            this->comboBox1->Size = System::Drawing::Size(71, 21);
            this->comboBox1->TabIndex = 0;
            // 
            // comboBox2
            // 
            this->comboBox2->FormattingEnabled = true;
            this->comboBox2->Items->AddRange(gcnew cli::array< System::Object^  >(5) {L"2", L"3", L"4", L"5", L"6"});
            this->comboBox2->Location = System::Drawing::Point(142, 62);
            this->comboBox2->Name = L"comboBox2";
            this->comboBox2->Size = System::Drawing::Size(71, 21);
            this->comboBox2->TabIndex = 1;
            // 
            // label1
            // 
            this->label1->AutoSize = true;
            this->label1->Location = System::Drawing::Point(30, 37);
            this->label1->Name = L"label1";
            this->label1->Size = System::Drawing::Size(83, 13);
            this->label1->TabIndex = 2;
            this->label1->Text = L"Material of Plate";
            // 
            // label2
            // 
            this->label2->AutoSize = true;
            this->label2->Location = System::Drawing::Point(30, 65);
            this->label2->Name = L"label2";
            this->label2->Size = System::Drawing::Size(95, 13);
            this->label2->TabIndex = 3;
            this->label2->Text = L"Thickness of Plate";
            // 
            // label4
            // 
            this->label4->AutoSize = true;
            this->label4->Location = System::Drawing::Point(219, 65);
            this->label4->Name = L"label4";
            this->label4->Size = System::Drawing::Size(23, 13);
            this->label4->TabIndex = 5;
            this->label4->Text = L"mm";
            // 
            // Form1
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(287, 138);
            this->Controls->Add(this->label4);
            this->Controls->Add(this->label2);
            this->Controls->Add(this->label1);
            this->Controls->Add(this->comboBox2);
            this->Controls->Add(this->comboBox1);
            this->Name = L"Form1";
            this->Text = L"Form1";
            this->ResumeLayout(false);
            this->PerformLayout();

        }
#pragma endregion
    };
}