function clearall(){
	document.getElementById('smile').style.border='';
	document.getElementById('hehe').style.border='';
	document.getElementById('cool').style.border='';
	document.getElementById('what').style.border='';
	document.getElementById('grimace').style.border='';
	document.getElementById('haha').style.border='';
	document.getElementById('love').style.border='';
	document.getElementById('misdoubt').style.border='';
	document.getElementById('stop').style.border='';
	document.getElementById('sad').style.border='';
	document.getElementById('cry').style.border='';
	document.getElementById('shame').style.border='';
}
function change(i){
	document.getElementById('face').value=i.src;
	clearall();
	i.style.border='1px #0080FF solid';
}
function is_html(content){
	p = /<(.+)>/i;
	if(content.search(p) == -1){
		return false;
	} else {
		return true;
	}
}
function check_form(f){
	if(f.username.value == ''){
		alert('Please input the username!');
		f.username.focus();
		return false;
	}else if(f.username.value == 'admin') {
		alert('The username(admin) is prohibited!');
		f.username.focus();
		return false;
	}
	if(f.email.value == ''){
		alert('Please input the email!');
		f.email.focus();
		return false;
	}else if(!is_email(f.email.value)) {
		alert('The email is not valad!');
		f.email.focus();
		return false;
	}
	if(f.content.value.length < 20){
		alert('Please input a valid comment! Your words is too short.');
		f.content.focus();
		return false;
	}else if(is_html(f.content.value)){
		alert('Please not input html code!');
		f.content.focus();
		return false;
	}
	
}