barkalov

<input type="text" required oninvalid="this.setCustomValidity('Wow!')">

<input type="text" required oninvalid="this.setCustomValidity('Wow')" oninput="setCustomValidity('')" />

function checkUndef(node) {
    if (node === undefined) return true;
    if (typeof node === 'object') {                
        for (var iNode in node) {
            if ( checkUndef(node[iNode]) ) return true;
        }
    }
    return false;            
}

<div id="new_social_link_template" style="display: none">
    <div class="social_link">
        ...          
    </div>    
</div>

var regexp = new RegExp('replaceme', 'g');
var time = new Date().getTime(); // получили timestamp        
var newSocialLinkHtml = $('#new_social_link_template').html();
newSocialLinkHtml = newSocialLinkHtml.replace(regexp, time);
$('#social_links').append(newSocialLinkHtml);

var bestCircleness = 0;
var bestX, bestY, bestRadius;

for (var x = 0; x < width; x++) {
    for (var y = 0; y < height; y++) {
        for (var radius = minRadius; radius <= maxRadius; radius++) {
            var circleness = getCircleness(x, y, radius);
            if (circleness > bestCircleness) {
                bestCircleness = circleness;
                bestX = x;
                bestY = y;
                bestRadius = radius;
            }
        }
    }
}