Validate time with regular expression in Javascript

 script language="javascript" type="text/javascript"
function CheckValTimeBlock(source, args)
{
if (args.Value > 4 && args.Value < 61)
{args.IsValid=true; }
else
args.IsValid=false;
}

function CheckValTime(source, args) {
var re = /^\d{1,2}[:]\d{2}([:]\d{2})?( [aApP][mM]?)?$/;
if (!re.test(args.Value)) { args.IsValid=false; }
else
args.IsValid=true;
}
script