REMOVE ALL FORM VALIDATION JAVASCRIPT.
Start by locating <script type="text/javascript">. It should be paired with a closing closing </script> tag.
Remove the script tags and all code in between it. Refer to below for sample JavaScript that would appear on your landing page. All of the below should be removed.
<script type="text/javascript">
var etr_sb=document.getElementsById ("etrSubmit"); function etr_ls (a) var b=document.getElementsByTagName ("head") [0], c=document.createElement ("script");c.src=a;
c.type="text/javascript";b.appendChild(c);}
function etr_submit () {var err=false;msg="The following errors were found:\n\n";
if(isEmpty(document.etrReg.x_emailaddress.value)) {er=true;ready=false;eMsg=eMsg+'-E-mail is Required.\n';}
if(isEmpty(document.etrReg.x_emailaddress.value)||!isEmailValid(document.etrReg.x_emailaddress.value)){er=true;ready=false;eMsg=eMsg+'-Email Address is Invalid.\n';}
if(isEmpty(document.etrReg.x_firstname.value)) {er=true;ready=false;eMsg=eMsg+'-First Name is Required.\n';}
if(isEmpty(document.etrReg.x_lastname.value)) {er=true;ready=false;eMsg=eMsg+'-Last Name is Required.\n';}
if(err==true){alert(msg);}else{var etrigueForm=new EtrigueForm(1090);etr_sb.disabled=true;etrigueFormSuccess=false;
etrigueForm.submitClassic("etrReg",function(dat){if(dat.err){etr_sb.disabled=false;return;}etrigueFormSuccess=true;
if(dat.thankYouPage){if(dat.repost){document.etrReg.action=dat.thankYouPage;
document.etrReg.submit();}else{window.location=dat.thankYouPage;}}});}}
function etr_trim(a){a=a.replace(/^\s+/,"");for(var b=a.length-1;b>=0;b--){if(/\S/.test(a.charAt(b)))
{a=a.substring(0,b+1);break}}return a;}function etr_empty(a){return a?(a=etr_trim(a),0===a.length):!0;}function
etr_valid(a){var b=/^([a-zA-Z0-9]+[a-zA-Z0-9_\-\.]*\@([a-zA-Z0-9]+[a-zA-Z0-9\_-]*\.)+[a-zA-Z0-9]+)$/;return
b.test(a)?!0:!1;}function etr_isint(a){return parseFloat(a)!=parseInt(a)||isNaN(a)?!1:!0;}function etr_ischkd(a){var
i,b=document.getElementsByName(a);for(i=0;i<b.length;i++){if(b[i].checked){return true;}}}
etr_ls("//trk.etrigue.com/etrigueForm.js");
</script>