I am creating a custom field in SharePoint 2007. I have seen other solutions where the current site URL was default value of a text field.
How can I get this current site URL?
I have got one answer whiches states that I shall use JavaScript, but where do I put the script?
I hope you can help.
BR
To answer 1
I am new to SharePoint and am not quiet sure where to put the java script. Normaly i just give the initial value to the field in the FieldEditor.cs file but how can I do this with the javascript?
Here follows a picute of my files.

I have tried to put it into FiledEditor.cs but this results in the value of myString is written in the top of the web page.
Here is my current code:
string myScript = "var currentUrl = document.URL; LabelLookupFieldTargetURLText.Text = currentUrl;";
Page.ClientScript.RegisterClientScriptBlock(LabelLookupFieldTargetURLText.GetType(), "LabelLookupFieldTargetURLTextJavaScript", myScript);
I found the answer my self. I don’t need to use a java script. I can just use SPContext.Current.Site.Url