try this
var myDoc = app.activeDocument;
var myPstyles = myDoc.allParagraphStyles;
var myAllPStyles = new Array();
for(i=1; i<myPstyles.length; i++)
{
var myParaName = myPstyles[i].name;
myAllPStyles.push(myParaName)
var temp = myAllPStyles.toString().split(",")
}
alert(temp.toString().replace (/\,/gi, "\r"))