function checkrequired(which) {
    	var pass=true;
    	if (document.images) {
    	for (i=0;i<which.length;i++) {
    		var tempobj=which.elements[i];
    		if ((tempobj.name=="name")||
     			(tempobj.name=="email")||
     			(tempobj.name=="company"))
     	   			{
    				if (((tempobj.type=="text"||tempobj.type=="textarea")&&
   				tempobj.value=='')||(tempobj.type.toString().charAt(0)=="s"&&
			    tempobj.selectedIndex==0)) 
    					{
    					pass=false;
    					break;
        				}
					if(tempobj.name=="email") {
						if(!(emailCheck(tempobj.value))) {
						pass=false;
						break;
						}
					}
					if(tempobj.name=="address") {
						replaceChars(which);
					}
          	}
       	}
    }
    if (!pass) {
	failedField=tempobj.name;
	if(failedField=="company") { alert("Please enter your company name.")}
	else {alert("Please make sure the "+failedField+" field was properly completed.");}
    return false;
    }
    else return true;
}


function replaceChars(form) {
	out = '"'; 			// replace this
	add = "''"; 		// with this
	temp = "" + form.address.value; // temporary holder
	while (temp.indexOf(out)>-1) {
		pos= temp.indexOf(out);
		temp = "" + (temp.substring(0, pos) + add + 
		temp.substring((pos + out.length), temp.length));
	}
	form.address.value = temp;
}

function emailCheck (emailStr) {
     var checkTLD=1;

    /* The following is the list of known TLDs that an e-mail address must end with.
    */

    var  knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;

    /* The following pattern is used to check if the entered e-mail address
    fits the user@domain format.  It also is used to separate the username
    from the domain. */

    var emailPat=/^(.+)@(.+)$/;

    /* The following string represents the pattern for matching all special
    characters.  We don't want to allow special characters in the address. 
    These characters include ( ) < > @ , ; : \ " . [ ] */

    var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";

    /* The following string represents the range of characters allowed in a 
    username or domainname.  It really states which chars aren't allowed.*/

    var validChars="\[^\\s" + specialChars + "\]";

    /* The following pattern applies if the "user" is a quoted string (in
    which case, there are no rules about which characters are allowed
    and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
    is a legal e-mail address. */

    var quotedUser="(\"[^\"]*\")";

    /* The following pattern applies for domains that are IP addresses,
    rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
    e-mail address. NOTE: The square brackets are required. */

    var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

    /* The following string represents an atom (basically a series of non-special
    characters.) */

    var atom=validChars + '+';

    /* The following string represents one word in the typical username.
    For example, in john.doe@somewhere.com, john and doe are words.
    Basically, a word is either an atom or quoted string. */

    var word="(" + atom + "|" + quotedUser + ")";

    // The following pattern describes the structure of the user

    var userPat=new RegExp("^" + word + "(\\." + word +
    ")*$");

    /* The following pattern describes the structure of a normal symbolic
    domain, as opposed to ipDomainPat, shown above. */

    var domainPat=new RegExp("^" + atom + "(\\." + atom
    +")*$");

    /* Finally, let's start trying to figure out if the supplied address is valid.
    */

    /* Begin with the coarse pattern to simply break up user@domain into
    different pieces that are easy to analyze. */

    var matchArray=emailStr.match(emailPat);

    if (matchArray==null) {

    /* Too many/few @'s or something; basically, this address doesn't
    even fit the general mould of a valid e-mail address. */

    alert("Email address seems incorrect (check @ and .'s)");
    return false;
    }
    var user=matchArray[1];
    var domain=matchArray[2];

    // Start by checking that only basic ASCII characters are in the (0-127).

    for (i=0; i<user.length; i++) {
    if (user.charCodeAt(i)>127) {
    alert("Ths username contains invalid characters.");
    return false;
       }
    }
    for (i=0; i<domain.length; i++) {
    if (domain.charCodeAt(i)>127) {
    alert("Ths domain name contains invalid characters.");
    return false;
       }
    }

    // See if "user" is valid 

    if (user.match(userPat)==null) {

    // user is not valid

    alert("The username doesn't seem to be valid.");
    return false;
    }

    /* if the e-mail address is at an IP address (as opposed to a symbolic
    host name) make sure the IP address is valid. */

    var IPArray=domain.match(ipDomainPat);
    if (IPArray!=null) {

    // this is an IP address

    for (var i=1;i<=4;i++) {
    if (IPArray[i]>255) {
    alert("Destination IP address is invalid!");
    return false;
       }
    }
    return true;
    }

    // Domain is symbolic name.  Check if it's valid.
     
    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) {
    alert("The domain name does not seem to be valid.");
    return false;
       }
    }

    /* domain name seems valid, but now make sure that it ends in a
    known top-level domain (like com, edu, gov) or a two-letter word,
    representing country (uk, nl), and that there's a hostname preceding 
    the domain or country. */

    if (checkTLD && domArr[domArr.length-1].length!=2 && 
    domArr[domArr.length-1].search(knownDomsPat)==-1) {
    alert("The address must end in a standard domain suffix or two letter " +
    "country.");
    return false;
    }

    // Make sure there's a host name preceding the domain.

    if (len<2) {
    alert("This address is missing a hostname!");
    return false;
    }

    // If we've gotten this far, everything's valid!
    return true;
    }