Changing the lead status into disqualified via SOAP request and some JS

Hi all,

We are writing a customized solution to achieve certain functionality. We have stumbled across peculiar problem, and we weren't able to found a direct and clean solution / explanation online. 

We are stuck somewhere around this piece of code:

<a:KeyValuePairOfstringanyType>");

request.push(" <c:key>Status</c:key>");
request.push(" <c:value i:type=\"a:OptionSetValue\">");
request.push(" <a:Value>3</a:Value>"); 
request.push(" </c:value>");

When implemented this function will set the lead status as 'Qualified Opportunity' but we want for function to set the different value.

How do we achieve that? And where is the list of Values that the function picks up? 

Is this a good direction: http://www.xrmcoaches.com/2012/01/changing-the-lead-qualification-status-values/ ; look at chart at the bottom. 

If it is, how do we set it up to set the lead status as lets say: 'Cannot Contact'

Thanks!