how to store string to text file

Hi All

Please find my script coding

var s= new Array();

var tPath = fPath.replace(".pdf",".txt")

for (var p = 0; p < this.numPages; p++)

{  

   s.push(this.getPageLabel(p));

}

var allText=s.join("\r");

I want store the variable "allText" to text file as a log. Please anyone can help in this.

Regards

Raj