js邮箱地址验证
js邮箱地址验证function jcv_checkemail(emailstr) {
if (emailstr.length == 0) {
return true;
}
// tld checking turned off by default
var checktld=0;
var knowndomspat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
var emailpat=/^(.+)@(.+)$/;
var specialchars="\(\)><@,;:\\\"\.\[\]";
var validchars="[^\s" + specialchars + "]";
var quoteduser="("[^"]*")";
var ipdomainpat=/^[(d{1,3}).(d{1,3}).(d{1,3}).(d{1,3})]$/;
var atom=validchars + '+';
var word="(" + atom + "|" + quoteduser + ")";
var userpat=new regexp("^" + word + "(\." + word + ")*$");
var domainpat=new regexp("^" + atom + "(\." + atom +")*$");
var matcharray=emailstr.match(emailpat);
if (matcharray==null) {
return false;
}
var user=matcharray[1];
var domain=matcharray[2];
for (i=0; i<user.length; i++) {
if (user.charcodeat(i)>127) {
return false;
}
}
for (i=0; i<domain.length; i++) {
if (domain.charcodeat(i)>127) {
return false;
}
}
if (user.match(userpat)==null) {
return false;
}
var iparray=domain.match(ipdomainpat);
if (iparray!=null) {
for (var i=1;i<=4;i++) {
if (iparray[i]>255) {
return false;
}
}
return true;
}
var atompat=new regexp("^" + atom + "$");
var domarr=domain.split(".");
var len=domarr.length;
for (i=0;i<len;i++) {
if (domarr[i].search(atompat)==-1) {
return false;
}
}
if (checktld && domarr[domarr.length-1].length!=2 &&
domarr[domarr.length-1].search(knowndomspat)==-1) {
return false;
}
if (len<2) {
return false;
}
return true;
}
补充：网页制作,js教程 
