function isValidEmail (emailStr) {
    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]

    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 domainArray=domain.match(domainPat)
    if (domainArray==null) {
        return false
    }

    var atomPat=new RegExp(atom,"g")
    var domArr=domain.match(atomPat)
    var len=domArr.length
    if (domArr[domArr.length-1].length<2 || 
        domArr[domArr.length-1].length>3) {
       return false
    }

    if (len<2) {
       return false
    }

    return true;
}

function trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}
function ltrim(stringToTrim) {
	return stringToTrim.replace(/^\s+/,"");
}
function rtrim(stringToTrim) {
	return stringToTrim.replace(/\s+$/,"");
}