function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") && anchor.getAttribute("rel")=="external")
     anchor.target = "_blank";
 }
}

window.onload = externalLinks;

//------------------------------------------------------------------------------

var Base64Chars =	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

//'Functions for encoding string to Base64
function base64_encode(strIn) {
	var c1, c2, c3, w1, w2, w3, w4, n, strOut = "";
	for (var n=0; n<strIn.length; n+=3) {
		c1 = strIn.charCodeAt(n);
		c2 = strIn.charCodeAt(n+1);
		c3 = strIn.charCodeAt(n+2);
		w1 = (c1 >> 2);
		w2 = (c1 & 3) * 16 + (c2 >> 4 );
		w3 = (strIn.length > n+1) ? (c2 & 15) * 4 + (c3 >> 6) : -1;
		w4 = (strIn.length > n+2) ? (c3 & 63) : -1;
		strOut += mimeencode(w1) + mimeencode(w2) + mimeencode(w3) + mimeencode(w4);
	}
	return strOut;
}

function mimeencode(intIn) {
	return (intIn >= 0) ? Base64Chars.charAt(intIn) : "";
}

function replaceEmail(strIn) {
	return strIn.replace("\.", " (tečka) ").replace("@", " (zavináč) ");
}

function makeHtml() {
	var strIn = document.forms[0].email.value;
	if (!strIn) {
		document.forms[0].email.focus();
		alert("Zadejte emailovou adresu");
		return false;
	}
	var strOut = "<a href=\"http://antispam.ooo.cz/?eml="+base64_encode(strIn)+"\" target=\"_blank\">"+replaceEmail(strIn)+"</a>";
	document.forms[0].text.value = strOut;
	return false;
}