Mine

<script type="text/javascript">
	function encrypt(form) {   
		var str = form.B1.value;   
		var prand = "";   
		var tils = "";   
		pp = 10;     
		str += 'tfytfkyf';       
		for(i = 0; i < str.length; i++) {        
			o = Math.round( ( str.charCodeAt(i) + str.charCodeAt(i+2) )/2 );    
			prand += o.toString();         
		}                   
		prand += prand.length.toString();          
		tils = prand.charAt(5) + prand.charAt(1) + prand.charAt(2) + prand.charAt(prand.length-1)                        
		<!--document.write(tils);-->
		document.getElementById('P1').value=tils;
	}
</script>