function insertTag(startTag, endTag, client_id) 
{
var myField = document.getElementById(client_id);
//IE support
if (document.selection) {
   myField.focus();
   sel = document.selection.createRange();
   sel.text = startTag+sel.text+endTag;
  }
//MOZILLA/NETSCAPE support
else if (myField.selectionStart || myField.selectionStart == '0') 
 {
   var startPos = myField.selectionStart;
   var endPos = myField.selectionEnd;
   myField.value = myField.value.substring(0, startPos)+
    startTag+ myField.value.substring(startPos, endPos)+ endTag+ myField.value.substring(endPos, myField.value.length);
 }
else 
 {
   myField.value += startTag + endTag;
 }
}