var digHeaderText = "";
function digAdDataContainer(insertionType, creativeHeader, creativeText) {
   this.insertionType   = insertionType;
   this.creative        = new Object();
   this.creative.header = creativeHeader;
   this.creative.text   = creativeText;

   if (typeof this.creative.header == "string" && this.creative.header.length > 0) {
      digHeaderText += this.creative.header + "\n";
   }
}

var digAdData = new Array();

document.write(digHeaderText);