function CheckForm(frm){
if(frm.author.value == ''){
alert ('Please enter your name.');
frm.author.focus();
return false;
}
if(frm.email.value == ''){
alert ('Please enter your email.');
frm.email.focus();
return false;
}
if(!frm.email.value.match(/^[\w]{1}[\w\.\-_]*@[\w]{1}[\w\-_\.]*\.[\w]{2,4}$/i)){
alert ('Invalid email.');
frm.email.focus();
return false;   
}
if(frm.comment.value == ''){
alert ('Please enter your message.');
frm.comment.focus();
return false;
}
}