To get the name of the first form in a document, use the forms property with You can try to run the following code to display the name −
Example
<!DOCTYPE html>
<html>
<body>
<form name ="formOne">
Name: <input type="text" name="my_name" value="Amit">
Subject: <input type="text" name="my_subject" value="Java">
<input type="submit" value="Submit">
</form>
<form name ="formTwo">
</form>
<script>
var val = document.forms.length;
document.write("<br>Number of forms in the document: "+val);
document.write("<br>Name of the first form: "+document.forms[0].name)
</script>
</body>
</html>