Yahoo Auto Suggest

Am using Yahoo Library for Auto Suggest and it is implementing well.. My Requirement is I've two radio buttons with a and b and its name is stype. When i selected a, I'll get a different suggestions, and if it is b, then a different suggestions. So, i called this onkeyup in a text box. and wrote the following code in the javascript function.

var  tagDataSource= new YAHOO.widget.DS_XHR("suggest", ["|"]);
tagDataSource.responseType = YAHOO.widget.DS_XHR.TYPE_FLAT;
tagDataSource.maxCacheEntries = 60;
tagDataSource.queryMatchSubset = true;
tagDataSource.scriptQueryParam = "query";
tagDataSource.scriptQueryAppend = "type="+stype;

I need to send the value of stype to that. But the problem is, The first time it works well. But when i changed the radio button and then when i typed in the text box, am getting the previous values and then again changing to the current values. I shouldn't get the previous values. What i've to do for this.??

THanks in Advance