function getSelection(ta){
	var bits = [ta.value,'','','']; 
    if(document.selection){
		var vs = '#$%^%$#';
        var tr=document.selection.createRange()
        if(tr.parentElement()!=ta) return null;
        bits[2] = tr.text;
        tr.text = vs;
        fb = ta.value.split(vs);
        tr.moveStart('character',-vs.length);
        tr.text = bits[2];
        bits[1] = fb[0];
        bits[3] = fb[1];
	}else{
		if(ta.selectionStart == ta.selectionEnd) return null;
        bits=(new RegExp('([\x00-\xff]{'+ta.selectionStart+'})([\x00-\xff]{'+(ta.selectionEnd - ta.selectionStart)+'})([\x00-\xff]*)')).exec(ta.value);
	}
	return bits;
}

function matchPTags(str)
  { str = ' ' + str + ' ';
    ot = str.split(/\[[B|U|I].*?\]/i);
    ct = str.split(/\[\/[B|U|I].*?\]/i);
    return ot.length==ct.length;
  }

function addPTag(ta,pTag)
  { bits = getSelection(ta);
    if(bits)
      { if(!matchPTags(bits[2]))
          { alert('\t\tInvalid Selection\nSelection contains unmatched opening or closing tags.');
            return;
          }
        ta.value = bits[1] + '[' + pTag + ']' + bits[2] + '[/' + pTag + ']' + bits[3];
      }
  }

function addCTag(ta,pTag)
  { bits = getSelection(ta);
    if(bits)
      { if(!matchPTags(bits[2]))
          { alert('\t\tInvalid Selection\nSelection contains unmatched opening or closing tags.');
            return;
          }
        ta.value = bits[1] + '[color=' + pTag + ']' + bits[2] + '[/color]' + bits[3];
      }
  }

function addFTag(ta,pTag){
	bits = getSelection(ta);
    if(bits)
      { if(!matchPTags(bits[2]))
          { alert('\t\tInvalid Selection\nSelection contains unmatched opening or closing tags.');
            return;
          }
        ta.value = bits[1] + '[font=' + pTag + ']' + bits[2] + '[/font]' + bits[3];
      }
}

function addSizesTag(ta,pTag){
	bits = getSelection(ta);
    if(bits)
      { if(!matchPTags(bits[2]))
          { alert('\t\tInvalid Selection\nSelection contains unmatched opening or closing tags.');
            return;
          }
        ta.value = bits[1] + '[size=' + pTag + ']' + bits[2] + '[/size]' + bits[3];
      }
}