[BETEPAH]

<button id="but">click</button>
<script>var but = document.getElementById('but');
but.addEventListener('mousedown', function () {
	but.setAttribute("data-_clk_",
        String( setTimeout(
            function() {
                but.removeAttribute("data-_clk_");
				alert('ta-dam');
            }, 3000) 
		)
    );
}, false);

but.addEventListener('mouseup', function () {
	if ( but.getAttribute("data-_clk_") ) {
		clearTimeout( Number( but.getAttribute("data-_clk_") ) );
		but.removeAttribute("data-_clk_");
	}
}, false);
</script>