function isFireFox()
{
	var d, moz, n, nua; 
	d = document; 
	n = navigator; 
	nua = n.userAgent; 
	if (!d.layers )
	{ 
	konq = ( nua.indexOf( 'Konqueror' )!= -1 ); 
	saf = ( nua.indexOf( 'Safari' )!= -1 ); 
	moz = ( nua.indexOf( 'Gecko' ) != -1 && !saf && !konq);
	}
	return moz;
}

function limitText(limitField, limitNum) 
{
	if(isFireFox())
	{
		if(limitField.value.length >limitNum - 2)
		{
			limitField.value=limitField.value.substr(0,limitNum);
			return true;
		}
		else
			return true;
	}
	else
	{
		var selection = document.selection.createRange( ).text;
		if(selection.length<=0 && limitField.value.length >limitNum-1)
		{
			return false;
		}
		else
			return true;
	}
}

function preventPaste(limitField,limitNum)
{
	var CanInsertLength; 
	var sData = window.clipboardData.getData("Text");
	var newData ; 
	if(!isFireFox())
	{
		var selection = document.selection.createRange( );
		var selectiontext = selection.text;
		CanInsertLength = limitNum - limitField.value.length +  selectiontext.length; 

		// if you can insert
		if(CanInsertLength >= 0)
		{
			// and what is in the clipboard is less than can be inserted
			if(sData.length<CanInsertLength)
			{
				newData = sData;
			} 
			// else, truncate string in the clipboard to the maximum length that can be inserted
			else
				newData = sData.substr(0,CanInsertLength);
			selection.text = newData;
		}
		return false; 
	}
}