My program is not going inside the "if" part and it is always going in the "else" part

I have done the connection with Oracle 10g Xe database through the following code.

Context ctx=new InitialContext();
DataSource ds=(DataSource)ctx.lookup("java:OracleDS");
Connection con=ds.getConnection(); 

String mob=request.getParameter("mob_no");
String pass=request.getParameter("pass");
Statement stmt=con.createStatement();

//checking login details
String sql="select * from user1 where mob_no='"+mob+"' and password='"+pass+"'";
ResultSet rs=stmt.executeQuery(sql);
String sql2="select * from postpaid where mob_no='"+mob+"'";
ResultSet rs2=stmt.executeQuery(sql2);

if(rs.isBeforeFirst())
{
    while(rs2.next())
    {  
        if(rs2.getInt(2)!=0)
        {
            out.println("You have total due of "+rs2.getInt(2));
            out.println("<a href=\"paybill.jsp\">Pay Bill</a>");
        }
        else {
            out.println("You have no dues!!!!!");
        }
    }
}
else
{
  out.println("Invalid login details.....<a href=\"#\">Back to home page</a>");
}

My program always shows the result "Invalid login Details"