How do i disable the paypal express checkout button after clicking it in shortcut.pht

[zeroloose]

Hi All,
I am new to magento. Please help me how to disable paypal express checkout button after clicking it once in the below mentioned file/code? Its urgent please.

File: magento\app\design\frontend\base\default\template\ paypal\express\shortcut.phtml
================================================== ===============
<p class="paypal-logo">
<?php $shortcutHtmlId = $this->getShortcutHtmlId() ?>
<?php if ($this->isOrPositionBefore()): ?>
<span class="paypal-or"><?php echo $this->__('-OR-');?></span>
<?php endif; ?>
<a id="<?php echo $shortcutHtmlId ?>” href="<?php echo $this->getCheckoutUrl()?>"><img src="<?php echo $this->getImageUrl()?>” alt="<?php echo Mage::helper('paypal')->__('Checkout with PayPal');?>” title="<?php echo Mage::helper('paypal')->__('Checkout with PayPal');?>” /></a>

<?php if ($this->isOrPositionAfter()): ?>
<span class="paypal-or"><?php echo $this->__('-OR-');?></span>
<?php endif; ?>
<?php if ($this->getConfirmationUrl() || $this->getIsInCatalogProduct()): ?>
<?php if ($this->getIsInCatalogProduct()): ?>
<input type="hidden" id="pp_checkout_url" name="return_url" value="” />
<?php endif; ?>
<script type="text/javascript\">

//<![CDATA[

Event.observe(’<?php echo $shortcutHtmlId ?>’, ‘click’, function(event) {

<?php if ($this->getConfirmationUrl()): ?>
if (confirm(’<?php echo Mage::helper('core')->jsQuoteEscape($this->getConfirmationMessage())?>’)) {
this.href = ‘<?php echo $this->getConfirmationUrl() ?>’;
}
<?php endif; ?>
<?php if ($this->getIsInCatalogProduct()): ?>
$(’pp_checkout_url’).value = this.href;
productAddToCartForm.submit(this);


event.stop();
<?php endif; ?>
});

//]]>
</script>
<?php endif; ?>
</p>
================================================== ========================
Regards,
Zeroloose