The method will be limited to DOM compliant browsers with javascript enabled. Tested to work with IE5+ and Gecko based NS6+ and Mozilla (>90% of current market and RIZING!!!) One can argue which method has more accessibility issues, but I assume you need to provide an alternative data access in both cases.
The advantages I see (besides the absence of frames) are:
1. Better interaction between input and output fields. For example, you have some data that has date field. When creating a control where user selects a date range, the server can be polled for available dates.
2. Minimum traffic. Server side script sends data only (with minimum delimiters). It does not concern with data presentation (HTML mark-up). This also allows you to separate data from presentation: easier to implement changes.
3. Truly background server polling. You can realize a queue of requests which will be transparent to the user.
4. Minimum page changes on update. The HTML element that contains new data can be created in the background and presented at once (node.style.display = 'block');
5. You can poll different server side scripts if needed
6. Your server side code becomes much cleaner - you no longer need to worry about HTML mark-up.
For example you have a DB of books with fields "author", "title", "price"
On the page load you want to present visitors with the list of authors, so you make your html page send a request
script.src = "dataServer.asp?request=authors"
Then your asp code would be something like that:
action=Request.QueryString('request');
if(action == 'authors')
{ SQLString = 'SELECT DISTINCT Books.author FROM Books';
rs.Open(SQLString,DBConnection,3,3)
authorlist = '';
while(!rs.EOF)
{ authorlist+=rs('author').Value + '$';
rs.MoveNext();
}
rs.Close();
%>displayAuthorList('<%=authorlist%>');<%
}
Then the function on the server side that displays the list of authors would be something like
function displayAuthorList(authorsString)
{ authors = authorsString.split('$');
listDiv = document.getElementById('authorList');
for(i=0; i<authors.length; i++)
{ with(listDiv.appendChild(document.createElement('a')))
{ href='dataServer.asp?request=Books&author='+escape(authors[i]);
appendChild(document.createTextNode(authors[i]))
}
}
}
Get the idea?
;)