JavaScript Required Field Validation on Web Form

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This script will check to see if the web user leaves any required fields blank, and if so, tell them which ones still need to be completed.

I was not satisfied with JavaScript Field Validation scripts I found online, so I wrote my own. I think it is easier to understand and adapt than others I have seen and will not break if you name your form, write a custom warning, or change the fieldnames to suit your purposes.

Code: 

<HTML>

<HEAD>
<script language="JavaScript">
<!-- *** JAVASCRIPT FIELD VALIDATION BY STEVEN K. TAJIRI
function validate(something) 
	{
	var warning = "Required fields : \n";
	var same = warning;
	if (something.field1.value=="") { warning += " ** field1 \n"; }
	if (something.field2.value=="") { warning += " ** field2 \n"; }
	if (something.field3.value=="") { warning += " ** field3 \n"; }
	if (something.field4.value=="") { warning += " ** field4 \n"; }

	if (warning == same) { return true; }
	else  { alert(warning); return false; }

	}
-->
</script>
</HEAD>

<BODY>

<form name="formname" action=" " onsubmit="return validate(this)">
Enter field1** : <input type="text" name="field1" size="12"><BR>
Enter field2** : <input type="text" name="field2" size="12"><BR>
Enter field3** : <input type="text" name="field3" size="12"><BR>
Enter field4** : <input type="text" name="field4" size="12"><BR>
** indicates a required field. <BR>
<BR>
<input type="submit" value="Submit">
</form>

</BODY>
</HTML>
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