Syntax error in INSERT INTO statement Error

I have a database connected successfully by "OLEDB" connection. I've used one table for the sign up form and it worked perfectly and then I used the other table with another form, but with the same code, with the differences that are needed, yet I keep getting this error:

Syntax error in INSERT INTO statement.

The error is for this part of the code:

{
    string sqlpost2 = "insert into postqr(Professor,Title,Body)";
    sqlpost2 += "value('" + postname + "','" + posttitle + "','" + postbody + "')";
    DBFunction.ChangeTable(sqlpost2, "DBS.accdb");
}

This is all of the code used in that page:

protected void Button9_Click(object sender, EventArgs e)
{
    string postname = this.Postuser.Text;
    string postpass = this.Postpass.Text;
    string posttitle = this.TOP.Text;
    string postbody = this.BOP.Text;
    string sqlstr2 = "select * from professors WHERE pname='" + postname + "' AND ppass='" + postpass + "'";

    DataTable dt1 = DBFunction.SelectFromTable(sqlstr2, "DBS.accdb");

    if (dt1.Rows.Count > 0)
    {
        string sqlpost2 = "insert into postqr(Professor,Title,Body)";
        sqlpost2 += "values('" + postname + "','" + posttitle + "','" + postbody + "')";
        DBFunction.ChangeTable(sqlpost2, "DBS.accdb");
    }
    else
        this.Label1.Text = "Posting on this wall is only allowed for professors and it seems that you're not one";          

    DataList1.DataBind();
}