/**
 * DHTML echeck script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */

function echeck(str)
{
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
	   alert("Invalid E-mail Address")
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   alert("Invalid E-mail Address")
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    alert("Invalid E-mail Address")
	    return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
	    alert("Invalid E-mail Address")
	    return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    alert("Invalid E-mail Address")
	    return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
	    alert("Invalid E-mail Address")
	    return false
	 }
	
	 if (str.indexOf(" ")!=-1){
	    alert("Invalid E-mail Address")
	    return false
	 }

		 return true					
}


function updateTotal()
{
	var total_field = document.getElementById('total');
	var density_field = document.getElementById('density');
	var total_value = 0;
	var density_value = 0;
	var temp_elem, temp_val;
	
	for( var i = 1; i <= 15; i++ )
	{
		var temp_val = parseFloat( document.getElementById(i+'_val').value );
		var temp_num = parseFloat( document.getElementById(i+'_den').value );
		
		if( !isNaN(temp_val) && !isNaN(temp_num) )
		{
			if( temp_val > 0 )
			{
				total_value = total_value + temp_val;
				density_value = density_value + ( temp_val / (100*temp_num) );
			}
			else
			{
				alert('Negative numbers are invalid.');
				document.getElementById(i+'_val').value = '';
			}
		}
	}
	
	
	total_field.value = total_value.toFixed(3);
	temp_density = 1 / density_value;
	
	if( total_field.value == 100 )
	{
		density_field.value = temp_density.toFixed(3);
	}
	else
	{
		density_field.value = '';
	}

	return false;
}


function verify()
{
	var email = document.getElementById('email');
	var fname = document.getElementById('fname');
	var lname = document.getElementById('lname');
	var city = document.getElementById('city');
	var state = document.getElementById('state');
	var country = document.getElementById('country');
	
	if ((email.value==null)||(email.value==""))
	{
		alert("Please Enter your Email Address");
		email.focus();
		return false;
	}
	
	if (echeck(email.value)==false)
	{
		email.value="";
		email.focus();
		return false;
	}
	
	if( document.getElementById('register').value == 'true' )
	{
		if( fname.value == '' || lname.value == '' || city.value == '' || state.value == '' || country.value == '' )
		{
			alert('You must enter all fields.');
			return false;
		}
	}
	
	return true;
}


function verify()
{
	var email = document.getElementById('email_recipient');
	var message = document.getElementById('message');
	
	if( document.getElementById('friend').value == 'true' )
	{
		if ((email.value==null)||(email.value==""))
		{
			alert("Please Enter your Email Address");
			email.focus();
			return false;
		}
		
		if (echeck(email.value)==false)
		{
			email.value="";
			email.focus();
			return false;
		}
	}
	else if( document.getElementById('indium').value == 'true' )
	{
		if( message.value == '' )
		{
			alert('Your message must not be empty.');
			message.focus();
			return false;
		}
		else if( message.value.length > 1024 )
		{
			alert('Your message must be shorter than 1024 characters.');
			message.focus();
			return false;
		}
	}
	
	return true;
}