function settarget(checkid,acls) {
/* This function sets the target= attribute of anchor
tags with the class 'acls' based on the checked
property of the element with id 'checkid'
*/
var atarg, elems, i
atarg = document.getElementById(checkid).checked ? '_blank' : '_self' ;
elems = document.getElementsByClassName(acls) ;
for (i = 0; i < (elems.length); i++)  {
elems[i].target = atarg ;
}