Making LaTeX tables using ERT in Lyx

Making LaTeX tables using ERT in Lyx

Hey I am trying to make the following LaTeX code work in Lyx 2.0:
\begin{table}[ht]
\caption{Nonlinear Model Results} 
\centering
\begin{tabular}{c c c c}
\hline\hline 
Case & Method\#1 & Method\#2 & Method\#3 \\ [0.5ex]
\hline
1 & 50& 837 & 970 \\
2 & 47 & 877 & 230 \\
3 & 31 & 25 & 415 \\
4 & 35 & 144 & 2356 \\
5 & 45 & 300 & 556 \\ [1ex]
\hline
\end{tabular}
\label{table:nonlin}
\end{table}
But when I try to makethe PDF it says that several things are wrong with the code so that Lyx can't create the PDF... Do I have to install certain packages in order to make the kind of tables that you can make in Latex? I do not want to use the tables in Lyx, because I think they are to inflexible!
Thanks, Lasse