var string1 = "adam.niklaus";
var string2 = "@";
var string3 = "niklaus";
var string4 = ".co";
var string5 = ".uk";
var string6 = string1 + string2 + string3 + string4 + string5;
document.write("<a href=" + "mail" + "to:" + string1 + string2 + string3 + string4 + string5 + ">" + string6 + "</a>");