var reEmail = /^.+\@.+\..+$/
function isEmpty(s)
				{   
					return ((s == null) || (s.length == 0))
				}
function isEmail (s)				
				{   
					if (isEmpty(s)) 
				       if (isEmail.arguments.length == 1) 
				       		return flase;
				       else 
				       		return (isEmail.arguments[1] == true);				    
				    else 
				    {
				       return reEmail.test(s)
				    }
				}

function CheckContactForm(){

	                if(document.f.txtName.value=="") {  
                        alert("Please enter your name");
                        document.f.txtName.focus();
                        return ;
                    }
                    
	                if(document.f.txtEmail.value=="" || !isEmail(document.f.txtEmail.value)) {  
                        alert('Please enter correct email address') ;
                        document.f.txtEmail.focus();
                        return ;
                    }
if(document.f.txtPhone.value=="") {  
                        alert("Please enter your phone number");
                        document.f.txtPhone.focus();
                        return ;
                    }
document.f.submit();
}