Incorrect syntax near ',' while using update query
<p>Following is my code.I have used class in my website.But i am getting error as "Incorrect syntax near ',' ".....can anyone tell me what is wrong in the code..</p>

<pre><code>protected void btnadd_Click(object sender, EventArgs e)
    {
        s1 = "Update tckt_tbl Set class='" + ddlclass.Text + "',dist=" + lbldist.Text + ",no_of_adults=" + ddladults.Text + ",no_of_senior=" + ddlsenior.Text + ",n1='" + txtn1.Text + "',";
        s1 += "n2='" + txtn2.Text + "',n3='" + txtn3.Text + "',n4='" + txtn4.Text + "',n5='" + txtn5.Text + "',n6='" + txtn6.Text + "',";
        s1 += "ag1=" + txtag1.Text + ",ag2=" + txtag2.Text + ",ag3=" + txtag3.Text + ",ag4=" + txtag4.Text + ",ag5=" + txtag5.Text + ",ag6=" + txtag6.Text + ",";
        s1 += "gen1='" + txtgen1.Text + "',gen2='" + txtgen2.Text + "',gen3='" + txtgen3.Text + "',gen4='" + txtgen4.Text + "',gen5='" + txtgen5.Text + "',gen6='" + txtgen6.Text + "',";
        s1 += "cn1='" + txtchn1.Text + "',cn2='" + txtchn2.Text + "',cag1=" + txtcag1.Text + ",cag2=" + txtcag2.Text + ",cgen1='" + txtcgen1.Text + "',cgen2='" + txtcgen2.Text + "' Where userid=" + Session["suser"].ToString() + "";
        con.ExecQuery(s1);
        Response.Redirect("tcktbook_itckt.aspx");
    }
</code></pre>
