[jQuery] Get Value. Please, is kind of urgent. Thanks.

Hello,

I have the following on my script:

$(document).ready(function() {

if (GBrowserIsCompatible()) {
$.getJSON("/Google/Map", Initialise);
} // Initialize Google Map

}

And in my HTML I have:
<input id="Place" name="Place" type="hidden" value="3" />

I want to run the JS code only if GBrowserIsCompatible() is defined.

If it is and if Place hidden value is not "" then I want to call:
$.getJSON("/Google/Map/{hidden_value}", Initialise);

In this case hidden value is 3.

If hidden value is "" then just call:
$.getJSON("/Google/Map", Initialise);

Please, could someone help me out?

Thanks,
Miguel