incorrect syntex near "="

i have twritten this code , but i am getting a exception when i try to debug my code ..

public partial class Article : System.Web.UI.Page
{
SqlConnection con;

SqlDataAdapter da1, da2;
DataSet ds=new DataSet();
LoginView lv;
public static string articleid;
string str=ConfigurationManager.ConnectionStrings["connect"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
articleid=Request.QueryString["ArticleID"];
lv =(LoginView) Master.FindControl("HeadLoginView");
if (!lv.Page.User.Identity.IsAuthenticated)
{
pnlComments.Visible = false;
hplreq.Visible = true;
}
else
{
pnlComments.Visible = true;
hplreq.Visible = false;
}

// displaying selected article
con = new SqlConnection(str);
con.Open();
da1 = new SqlDataAdapter("select * from Articles where ArticleID = "+ articleid,con);
ds.Clear();da1.Fill(ds,"Article");
imgArticle.ImageUrl = ds.Tables["Article"].Rows[0]["ImageUrl"].ToString();
lblBody.Text = ds.Tables["Article"].Rows[0]["Body"].ToString();
lblTitle.Text = ds.Tables["Article"].Rows[0]["Title"].ToString();
lblAddedBy.Text = ds.Tables["Article"].Rows[0]["AddedBy"].ToString();
lblAddedDate.Text = ds.Tables["Article"].Rows[0]["AddedDate"].ToString();

// displaying others articles
da2 = new SqlDataAdapter("seletc 8 from Articles where NOT ArticleID = "+articleid,con);
ds.Clear();
da2.Fill(ds,"Articles");
lstArticle.DataSource = ds;
lstArticle.DataBind();
HyperLink hplread=(HyperLink) lstArticle.FindControl("HyperLink1");
hplread.NavigateUrl = "~/Account/Login.aspx?ReturnUrl=~/Article.aspx?ArticleID="+articleid;
con.Close();

}

i have bold the line where i am getting the exception . what is wrong in this code . please help me