function but()
{
 if(document.f1.name.value=="")
  	{
     alert("First Name should be given");
	 document.f1.name.focus()
	 return false;
	}
 if((document.f1.email.value=="")||(document.f1.email.value.indexOf('@')==-1)||
    (document.f1.email.value.indexOf('.')==-1)){
     alert("please give your email address eg:myid@domain.com");
	 document.f1.email.focus()
	 return false;
    }
if(document.f1.subject.value=="")
 	{
     alert("Enter your Subject");
	 document.f1.subject.focus()
	 return false;
	}
if(isNaN(document.f1.phone.value))
 	{
     alert("Enter Valid Phone No");
	 document.f1.phone.focus()
	 return false;
	}

if(document.f1.feedback.value=="")
 	{
     alert("Enter your Feedback");
	 document.f1.feedback.focus()
	 return false;
	}
	
return true;
}