This is how we make the form input fields in CakePHP more like Excel Currency Format cells http://stackoverflow.com/a/1162744/80353

EditView.php

<div class="voucherCategories container_16">
  <div class="grid_16" style="text-align: center" > 
		<?php echo $this->element('products_link_bar'); ?>
		<h2><?php echo __('Edit ' . $this->Form->value('VoucherCategory.name')); ?></h2>
	</div>
<?php echo $this->Form->create('VoucherCategory'); ?>
	<fieldset class="grid_16">

	<?php
		echo $this->Form->input('id');
		echo $this->Form->input('year_id');
		echo $this->element('select_projects', array('projects' => $allProjects, 'selected' => $selectedProjects));
		echo $this->Form->input('name');
		echo $this->Form->input('site_count');
		echo $this->Form->input('net_total_after_payment_terms', array('class' => "niceCurrencyFormat", 'ref' => $this->Form->value('VoucherCategory.net_total_after_payment_terms'),
			'type' => 'text'));
		echo $this->Form->input('voucher_value', array('class' => "niceCurrencyFormat", 'ref' => $this->Form->value('VoucherCategory.voucher_value'),
			'type' => 'text'));

	?>
	</fieldset>
<?php echo $this->Form->end(__('Submit')); ?>
</div>
<?php $this->append('scriptBottom'); ?>
<script type="text/javascript">
	$(document).ready(function() {
		$.each($(".niceCurrencyFormat"), function (index, value){
			var originalNumber = $(value).attr('ref');
			var niceNumber = '$' + formatNumber(originalNumber, 0, 2, true);
			$(value).val(niceNumber);
		});
		$(".niceCurrencyFormat").focus(function() {
			$(this).val($(this).attr('ref'));
		});
		$(".niceCurrencyFormat").focusout(function() {
			var originalNumber = $(this).attr('ref');
			var niceNumber = '$' + formatNumber(originalNumber, 0, 2, true);
			$(this).val(niceNumber);
		});
		$(".niceCurrencyFormat").keyup(function(event) {
			var currentValue = $(this).val();
			$(this).attr('ref', currentValue);
		});
		$("#VoucherCategoryEditForm").on('submit',function (){
			$.each($(".niceCurrencyFormat"), function (index, value){
				var originalNumber = $(value).attr('ref');
				$(value).val(originalNumber);
			});
		});
	});
</script>
<?php $this->end('scriptBottom'); ?>