Need help with loadxml

i have a javascript code that creates chaining drown down list and the end result is an xml file name that gets sent to a dynamic text box on my flash file with setvariable. everything works fine the name appears in my text box on the swf file. now i want to load that xml file name so i use

myDisplay.loadXML(myText.text);

but for some reason nothing gets loaded. i am assuming that some how this needs to get refreshed or something but i can’t fine anything online that would point me to the right direction. i know if i manually put the xml file name it works.

myDisplay.loadXML(“myXml.xml”);

does anyone know what i am doing wrong here?