function mailadr() {
 var mailt = "mailto:";
 var user = "service";
 var xat = "@";
 var domain = "webdesign-piechowski.de";
 document.getElementById("mailadr").href = mailt+user+xat+domain;
}

function mailadr2() {
 var mailt = "mailto:";
 var user = "service";
 var xat = "@";
 var domain = "webdesign-piechowski.de";
 var subj = "?subject=Projekt%20X&body=Bitte%20geben%20Sie%20mir%20weitere%20Informationen%20zum%20Projekt%20X%20unter%20folgender%20Telefonnummer: ";
 document.getElementById("mailadr").href = mailt+user+xat+domain+subj;
}