why xsl remade links out family base?

<a>
 <xsl:attribute name="href">
 <xsl:value-of select="link" />
 </xsl:attribute>
 <xsl:attribute name="target">new</xsl:attribute>
 <xsl:value-of select="title" />
 </a>

thats template, code:

 sb.append("<title>");
 sb.appendformat("{0} - {1}", f.username, f.pointtypedesc);
 sb.append("</title>");
 sb.append("<link>");
 sb.appendformat("{0}", httputility.urlencode(url));
 sb.append("</link>");

url ""

but renders as: ""

any ideas?