function validateForm(){
    var valid = true; 
    
      
    if ( document.ContactForm.name.value == "" )
    {
        document.ContactForm.errorName.style.fontSize='10px';
        
        valid = false;
    }else 
        document.ContactForm.errorName.style.fontSize='0px';
            
            
    var str = document.ContactForm.email.value;    
    var filter = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
 
    if(!filter.test(str)){
        document.ContactForm.errorEmail.style.fontSize='10px';
        valid= false;
    }else 
        document.ContactForm.errorEmail.style.fontSize='0px';
    
      
    str = document.ContactForm.contact.value;      
    if( isNaN(str) || str=="" || !(str.length==9) ){
        
        document.ContactForm.errorContact.style.fontSize='10px';
        valid = false;
    }else 
        document.ContactForm.errorContact.style.fontSize='0px';
    
    str = document.ContactForm.assunto.value;
   
    if(str.length<10){
        document.ContactForm.errorAssunto.style.fontSize='10px';
        valid = false;
    }else 
        document.ContactForm.errorAssunto.style.fontSize='0px';
    
    
    return valid;
}