function validateMailAddr(emailad) {
    	var exclude=/[^@\-\.\w]|^[_@\.\-]|[\._\-]{2}|[@\.]{2}|(@)[^@]*\1/;
     	var check=/@[\w\-]+\./;
    	var checkend=/\.[a-zA-Z]{2,3}$/;
     	var arrayOfAddresses = emailad.split(',');
    	for(var i=0; i < arrayOfAddresses.length; i++) {
     	    if(((arrayOfAddresses[i].search(exclude) != -1)||(arrayOfAddresses[i].search(check)) == -1)||(arrayOfAddresses[i].search(checkend) == -1)) {
     		    alert("E-mailová adresa není platná!");
            posli = false;
    		    return;
     		}
    	}
    	posli = true;
    }