Javascript meta change from with in frame

I have this problem to solve:

• mainsrc.html is loaded into a frame in a frameset in secsrc.html
• I can only change mainsrc.html
• I have to add a meta to the head of secsrc.html

Is this possible through javascript?

the script that I have so far is below, its located in mainsrc.html body, as you can see this doesnt work as it just adds the meta to mainsrc.html's head and not secsrc.html's head:

...
<script type="text/javascript">
if (document.createElement &&
(meta = document.createElement('meta'))) {

meta.name = "dummy";
meta.content = "1234";

document.getElementsByTagName('head').item(0).appendChild(meta);
}
</script>
...