function isValid(string,which) 
{
	allowed = '0123456789';
	wrong = 0;
	string = string.value;
	for (var i=0; i< string.length; i++) {
       if (allowed.indexOf(string.charAt(i)) == -1)		  
		wrong = 1;
    }
	if (wrong)
	{
		if(which == '12exp'){ form3.exp1235.value = '0';}
		if(which == '24exp'){ form3.exp2435.value = '0';}
		if(which == '36exp'){ form3.exp3635.value = '0';}
		if(which == '15aps'){ form5.ex15aps.value = '0';}
		if(which == '25aps'){ form5.ex25aps.value = '0';}
		if(which == '40aps'){ form5.ex40aps.value = '0';}

		if(which == '12es'){ form3.es1235.value = '0';}
		if(which == '24es'){ form3.es2435.value = '0';}
		if(which == '36es'){ form3.es3635.value = '0';}
		if(which == '15es'){ form5.es15aps.value = '0';}
		if(which == '25es'){ form5.es25aps.value = '0';}
		if(which == '40es'){ form5.es40aps.value = '0';}

		if(which == '42re'){ form6.re35.value = '0';}
		if(which == '57en'){ form6.en57.value = '0';}
		if(which == '68en'){ form6.en68.value = '0';}
		if(which == '810en'){ form6.en810.value = '0';}
		if(which == '812en'){ form6.en812.value = '0';}
		
		if(which == '5aps'){ form9.aps5.value = '0';}
		if(which == '8aps'){ form9.aps8.value = '0';}
		if(which == 'classic'){ form9.reclass.value = '0';}
		if(which == 'hd'){ form9.rehd.value = '0';}
		if(which == 'pan'){ form9.repan.value = '0';}
	}
	liveUpdate();
}