Random banner links: How to open in new tab/window

Question

I've added a random banner to a site I'm experimenting with, and I've got it to randomly load the images. The links are all set and working, but they open in the same window or tab. Is there a way to tell it to open the linked site in a new window or tab?
Here's the script:
<script language="JavaScript">
<!--
function random_imglink(){
  var myimages=new Array()
  //specify random images below.
  myimages[1]="img/banner-1.jpg"
  myimages[2]="img/banner-2.jpg"
  myimages[3]="img/banner-3.jpg"
  myimages[4]="img/banner-4.jpg"
  myimages[5]="img/banner-5.jpg"
  //specify corresponding links below
  var imagelinks=new Array()
  imagelinks[1]="http://www.website.com"
  imagelinks[2]="http://www.website.com"
  imagelinks[3]="http://www.website.com"
  imagelinks[4]="http://www.website.com"
  imagelinks[5]="http://www.website.com"
  var ry=Math.floor(Math.random()*myimages.length)
  if (ry==0)
     ry=1
     document.write('<a href='+'"'+imagelinks[ry]+'"'+'><img src="'+myimages[ry]+'" border=none></a>')
  random_imglink()
//-->
</script>

Answer 1

I think part of your problem might lie in the way you are trying to use your quotation marks.  It appears you are trying to have the single quotes do what double quotes should be doing.
document.write("<a href='"+imagelinks[ry]+"' target='_blank'><img src='"+myimages[ry]+"' border='none'></a>
If you want to have doublequotes appear in code as doublequote characters you can try slashing them to have them read literally... \"
document.write("<a href=\""+imagelinks[ry]+"\" target=\"_blank\"><img src=\""+myimages[ry]+"\" border=\"none\"></a>