function setTargetTextBox() {
  var opener = window.opener;
  var targetTextBoxId 
    = 'ctl00_ContentPlaceHolder1_' + opener.targetTextBoxId;
  window.targetTextBox = opener.document.getElementById(targetTextBoxId);
}
    
function addToTextBox(event) {
  var e = event || window.event;
  var target = e.target || e.srcElement;
  
  if (target.tagName.toLowerCase() == 'a') {
    var selectedText = target.firstChild.nodeValue;
    
    if (selectedText.search(/\s+/) != -1) {
      selectedText = '"' + selectedText + '"'
    }
    
    var targetValue = window.targetTextBox.value;    
    if (targetValue != '') {
      targetValue += " OR ";
    }
    targetValue += selectedText;
          
    window.targetTextBox.value = targetValue;
  }
}