Ok, i solved this problem with js. My solution:
<script type="text/javascript">
function prAv()
{
var pID=<xsl:value-of select="ProductID" xmlns:xsl="#unknown" />;
var vID=<xsl:value-of select="VariantID" xmlns:xsl="#unknown" />;
var cID=<xsl:value-of select="CustomerID" xmlns:xsl="#unknown" />;
var mail=document.getElementById('inputSom').value;
var url="/CuAv.aspx?pID="+pID+"&cID="+cID+"&vID="+vID+"&mail="+mail;
window.location.href =url;
}
</script>
<a id="inputSom" href="javascript:prAv();">Go to</a>