function confirmValid(name, email, age, sex) {
	 var str = email.value
	 var atsign = str.indexOf('@') // get position of @ sign in string
	 var dot = str.lastIndexOf('.')
	
			if (name.value == "") { alert('Please enter your name'); return false; }
			else if (age.value == "") { alert('Please enter your age'); return false; }
			else if (isNaN(age.value) || parseInt(age.value) < 18) { alert('Please enter a valid age'); return false; }
	 		else if ((atsign < 1) ||                    // '@' cannot be in first position
	     		(dot <= atsign + 1) ||             // Must be at least one valid char btwn '@' and '.'
	     		(str.charAt(dot - 1) == '.') ||   // Two dots can not appear in consecutive positions
	     		(dot == (str.length - 1)) ||       // Must be at least one valid char after '.'
	     		(str.indexOf(' ')  != -1) ||       // No empty spaces permitted
	     		(str.indexOf(',')  != -1) ||       // No commas permitted
	     		(str.indexOf('&quot;')  != -1) ||   // No double quotes permitted
	     		(str.indexOf('\'')  != -1))        // No single quotes permitted
	    	{  
				alert("Please enter a valid email address")
	   		return false;}
		return true;
	}