function RefreshCaptcha(valImageId, valTextboxId) {
    //Change CAPTCHA image
	var objImage = document.getElementById(valImageId);
	if (objImage == undefined) {
		return;
	}
	var now = new Date();
	objImage.src = objImage.src.split('?')[0] + '?x=' + now.toUTCString();
    
    //Set focus back to textbox
	var objTextbox = document.getElementById(valTextboxId);
	if (objTextbox == undefined) {
	    return;
	}
	objTextbox.focus();
		
}