Controlling when a footnote appears in beamer presentation

Question

In my beamer presentation, I have multiple slides of the form

  \frame{
  \frametitle{FRAME TITLE HERE}
  \begin{itemize}
  \begin{columns}
  \begin{column}{2in}
  \item \onslide<1->
  TEXT FOR ITEM 1 HERE WITH REFERENCE TO A FOOTNOTE USING \footnotemark
  \item \onslide<2-> 
  TEXT FOR ITEM 2 HERE WITH REFERENCE TO A FOOTNOTE USING \footnotemark
  \end{column}

  \begin{column}{1.6in}
  \onslide<1->
  ADD FIGURE 1 HERE
  \onslide<2->
  ADD FIGURE 2 HERE
  \end{column}
  \end{columns}

  \footnotetext[1]{TEXT FOR FIRST FOOTNOTE HERE}
  \footnotetext[2]{TEXT FOR SECOND FOOTNOTE HERE}
  \end{itemize}
  }

However, when I do this, both footnotes appear on slide 1, even though the \footnotemark for the second footnote appears in the main text on slide 2. Ideally, I would like the second footnote to appear only when the second slide comes up. Any suggestions?

Answer 1

In order to remove this question from the list of unanswered questions, here the comments turned into an answer.

\documentclass{beamer}

\begin{document}

  \begin{frame}
    \frametitle{FRAME TITLE HERE}
    \begin{itemize}
            \item \onslide<1-> TEXT FOR ITEM 1 HERE WITH REFERENCE TO A FOOTNOTE USING \footnotemark
            \item \onslide<2-> TEXT FOR ITEM 2 HERE WITH REFERENCE TO A FOOTNOTE USING \footnotemark
        \item \onslide<3-> TEXT FOR ITEM 3 HERE
        \footnotetext[1]{TEXT FOR FIRST FOOTNOTE HERE}
        \only<2->{\footnotetext[2]{TEXT FOR SECOND FOOTNOTE HERE}}
    \end{itemize}
  \end{frame}

\end{document}

If you want the footnote box to keep its size, not increasing every slide, use the following instead:

\footnotetext[2]<2->{TEXT FOR SECOND FOOTNOTE HERE}