使用ms访问数据库插入到语句中的语法错误

Question

我试图将数据插入ms访问数据库，但我在insert into语句中不断出现语法错误。

代码：

using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.OleDb;

public partial class Default2 : System.Web.UI.Page
{
    OleDbConnection mycon;
    protected void Page_Load(object sender, EventArgs e)
    {
        mycon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\sidd\Desktop\Database1.mdb");

    }
    protected void Button1_Click(object sender, EventArgs e)
    {

        string insertcmd = "insert into comp (pro_ps,pro_type,pro_nam,pro_det) values( '"+TextBox1.Text +"','"+TextBox1.Text  +"','"+TextBox1.Text+"','"+TextBox1.Text+"')";
        OleDbCommand cmd = new OleDbCommand(insertcmd, mycon);
        mycon.Open();
        cmd.ExecuteNonQuery();
        TextBox2.Text = "DONE";
    }

}

数据库：