Combo Box in DataGridview

this.dataGridView1.AutoGenerateColumns = false;
            this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
            this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
            this.Column1,
            this.empDataGridViewTextBoxColumn,
            this.empnameDataGridViewTextBoxColumn,
            this.noofleaveDataGridViewTextBoxColumn});
            this.dataGridView1.DataSource = this.employeeBindingSource;
            this.dataGridView1.Location = new System.Drawing.Point(28, 12);
            this.dataGridView1.Name = "dataGridView1";
            this.dataGridView1.Size = new System.Drawing.Size(452, 150);
            this.dataGridView1.TabIndex = 0;