if (res == 1) {
   document.write("<LINK rel=stylesheet href=\"locaties_css/amstel1.css\" type=\"text/css\">"); }

else if (res == 2) {
   document.write("<LINK rel=stylesheet href=\"locaties_css/amstel2.css\" type=\"text/css\">"); }

else if (res == 3) {
   document.write("<LINK rel=stylesheet href=\"locaties_css/amstel3.css\" type=\"text/css\">"); }

else if (res == 4) {
   document.write("<LINK rel=stylesheet href=\"locaties_css/amstel4.css\" type=\"text/css\">"); }

else if (res == 5) {
   document.write("<LINK rel=stylesheet href=\"locaties_css/amstel5.css\" type=\"text/css\">"); }