Validation of multiple Mandatory fields on a web form to Lead

Validation of multiple Mandatory fields on a web form to Lead

I'm trying to have 3 fields mandatory in my web form: First Name, Last Name and Phone number.

I checked on the help base of Zoho and found:  https://crmkbase.zoho.com/link/can-certain-fields-in-the-web-forms-be-made-mandatory

I inserted this code but it only works for Last name and if I leave the others empty, it accepts the entry:

<script>

// if you need to have some fields to be mandatory, please add them here within quotes ("") separate by comma (,).

var fieldIdarray=new Array("Last Name","First Name","Phone"); //This is used for the Validation.
 
var fieldNamearray=new Array("Last Name","First Name","Phone number"); //This is used for alert messages.

function validate()
{
 
for(var i=0;i<fieldIdarray.length;i++)

 {
  var value=document.getElementsByName(fieldIdarray[i])[0].value;

 if(value=="" || value =="-None-" )

  {
 
    alert(fieldNamearray[i]+" cannot be empty");return false;

   }
  
  }

 }

</script>

Then I noticed that there is another native validation at the end of the code which seems to work exactly the same but I don't know how to duplicate it to add the validation of the two others fields:

   <script> var mndFileds=new Array('Last Name');var fldLangVal=new Array('Last Name');function checkMandatery(){for(i=0;i<mndFileds.length;i++){ var fieldObj=document.forms['WebToLeads650260000000256159'][mndFileds[i]];if(fieldObj) {if(((fieldObj.value).replace(/^\s+|\s+$/g, '')).length==0){alert(fldLangVal[i] +' can not be empty'); fieldObj.focus(); return false;}else if(fieldObj.nodeName=='SELECT'){if(fieldObj.options[fieldObj.selectedIndex].value=='-None-'){alert(fldLangVal[i] +' can not be « None »'); fieldObj.focus(); return false;}}}}}</script>

Any idea?

Thanks to the developers able to help me with the code because I'm definitly not a coder ;-)

Valérie

(I'm French so any help in French or in detailed English would help me!! LOL)