Form Validator Producing Errors ('null' is ull or not an object" and "object doesn't support this property or method")

function checkEmail (strng) {
var email = document.create_account.email.value;
var error = "";
	if (strng == "") {
	   error = "You didn't enter an email address.\n";
	}
 
var emailFilter=/^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.\n";
    } else {
//test email for illegal characters
       var illegalChars = /[\(\)\<\>\,\;\:\\\"\[\]]/
         if (strng.match(illegalChars)) {
          error = "The email address contains illegal characters.\n";
       }
    }
inlineMsg('email',error,3);
return false;  
}
 
// phone number - strip out delimiters and check for 10 digits
function checkPhone (strng) {
var phonenum = document.create_account.phone.value;
var error = "";
	if (strng == "") {
	   error = "You didn't enter a phone number.\n";
	}
 
var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); //strip out acceptable non-numeric characters
    if (isNaN(parseInt(stripped))) {
		error = "The phone number contains illegal characters.";
    }
    if (!(stripped.length == 10)) {
		error = "The phone number is the wrong length. Make sure you included an area code.\n";
    } 
inlineMsg('phonenum',error,3);
return false;    
}
 
// password - between 6-8 chars, lowercase, and numeral
function checkPassword (strng) {
var pass = document.create_account.password.value;
var error = "";
	if (strng == "") {
		error = "You didn't enter a password.\n";
	}
var illegalChars = /[\W_]/; // allow only letters and numbers
	if (strng.length <= 6) {
		error = "The password must contain at least 6 characters.\n";
	}
	else if (illegalChars.test(strng)) {
		error = "The password contains illegal characters.\n";
	}
inlineMsg('pass',error,3);
return false;    
}    
 
//function samePassword (strng) {
//var passw2 = document.create_account.pass2.value;
//	if (strng != document.create_account.password.value) {
//       error = "The password does not match.\n";
//	}
//inlineMsg('passw2',error,3);
//return false;    
//}  
 
var MSGTIMER = 20;
var MSGSPEED = 5;
var MSGOFFSET = 3;
var MSGHIDE = 3;
 
// build out the divs, set attributes and call the fade function //
function inlineMsg(target,string,autohide) {
  var msg;
  var msgcontent;
  if(!document.getElementById('msg')) {
    msg = document.createElement('div');
    msg.id = 'msg';
    msgcontent = document.createElement('div');
    msgcontent.id = 'msgcontent';
    document.body.appendChild(msg);
    msg.appendChild(msgcontent);
    msg.style.filter = 'alpha(opacity=0)';
    msg.style.opacity = 0;
    msg.alpha = 0;
  } else {
    msg = document.getElementById('msg');
    msgcontent = document.getElementById('msgcontent');
  }
  msgcontent.innerHTML = string;
  msg.style.display = 'block';
  var msgheight = msg.offsetHeight;
  var targetdiv = document.getElementById(target);
  targetdiv.select();
  var targetheight = targetdiv.offsetHeight;
  var targetwidth = targetdiv.offsetWidth;
  var topposition = topPosition(targetdiv) - ((msgheight - targetheight) / 2);
  var leftposition = leftPosition(targetdiv) + targetwidth + MSGOFFSET;
  msg.style.top = topposition + 'px';
  msg.style.left = leftposition + 'px';
  clearInterval(msg.timer);
  msg.timer = setInterval("fadeMsg(1)", MSGTIMER);
  if(!autohide) {
    autohide = MSGHIDE;  
  }
  window.setTimeout("hideMsg()", (autohide * 1000));
}
 
// hide the form alert //
function hideMsg(msg) {
  var msg = document.getElementById('msg');
  if(!msg.timer) {
    msg.timer = setInterval("fadeMsg(0)", MSGTIMER);
  }
}
 
// face the message box //
function fadeMsg(flag) {
  if(flag == null) {
    flag = 1;
  }
  var msg = document.getElementById('msg');
  var value;
  if(flag == 1) {
    value = msg.alpha + MSGSPEED;
  } else {
    value = msg.alpha - MSGSPEED;
  }
  msg.alpha = value;
  msg.style.opacity = (value / 100);
  msg.style.filter = 'alpha(opacity=' + value + ')';
  if(value >= 99) {
    clearInterval(msg.timer);
    msg.timer = null;
  } else if(value <= 1) {
    msg.style.display = "none";
    clearInterval(msg.timer);
  }
}
 
// calculate the position of the element in relation to the left of the browser //
function leftPosition(target) {
  var left = 0;
  if(target.offsetParent) {
    while(1) {
      left += target.offsetLeft;
      if(!target.offsetParent) {
        break;
      }
      target = target.offsetParent;
    }
  } else if(target.x) {
    left += target.x;
  }
  return left;
}
 
// calculate the position of the element in relation to the top of the browser window //
function topPosition(target) {
  var top = 0;
  if(target.offsetParent) {
    while(1) {
      top += target.offsetTop;
      if(!target.offsetParent) {
        break;
      }
      target = target.offsetParent;
    }
  } else if(target.y) {
    top += target.y;
  }
  return top;
}
 
// preload the arrow //
if(document.images) {
//  arrow = new Image(7,80); 
  arrow.src = "../image/misc_list_type_style.png"; 
}
 
 
 
<form name="create_account">
 <ul>
  <li class="account_info_label">
	<div class="account_info_personal">Email Address: <input id="email" name="email" value="" type="text" onchange="checkEmail(this);this.blur();this.focus()" /></div>
	<div class="account_info_privacy"><a href="index.php?module=privacy" target="_blank">Privacy Policy</a></div>
  </li>
  <br clear="all" />
  <li class="account_info_label">
	<div class="account_info_personal">Choose Password: <input id="password" name="password" value="" type="password" onchange="checkPassword(this);this.blur();this.focus()" /></div>
	<div class="account_info_personal_right">Re-Enter Password: <input id="password2" name="password2" value="" type="password" onchange="samePassword(this);this.blur();this.focus()" /></div>
  <br clear="all" />
	<span class="account_info_optional">Password must be at least 6 characters.</span>
  </li>
  <br clear="all" />
  <li class="account_info_label">
	<div class="account_info_personal">Phone Number: <input id="phone" name="phone" value="" type="text" onchange="checkPhone(this);this.blur();this.focus()" /></div>
	<div class="account_info_personal_right">Fax Number: <span class="account_info_optional">(optional)</span> <input id="fax" name="fax" value="" type="text" /></div>
  </li>
</ul>
</form>