function emailCheck(emailStr) {
          var sw = true;
          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 +")*$");
          var matchArray=emailStr.match(emailPat);
          if (matchArray==null) { sw = false; return sw; }
          var user=matchArray[1];
          var domain=matchArray[2];
          for (i=0; i<user.length; i++) {
          if (user.charCodeAt(i)>127) sw = false;
          }
          for (i=0; i<domain.length; i++) {
          if (domain.charCodeAt(i)>127) sw = false;
          }
          if (user.match(userPat)==null) sw = false;
          var IPArray=domain.match(ipDomainPat);
          if (IPArray!=null) {
          for (var i=1;i<=4;i++) {
          if (IPArray[i]>255) sw = false;
          }
          return true;
          }
          var atomPat=new RegExp("^" + atom + "$");
          var domArr=domain.split(".");
          var len=domArr.length;
          for (i=0;i<len;i++)
          {
          if (domArr[i].search(atomPat)==-1) sw = false;
          }
          if (checkTLD && domArr[domArr.length-1].length!=2 &&
          domArr[domArr.length-1].search(knownDomsPat)==-1) sw = false;
          if (len<2) sw = false;
          return sw;
}