// JavaScript Document

var whitespace = " \t\n\r";
var defaultEmptyOK = false;

	function isWhitespace (s)	{   
		var i;
	
		// Is s empty?
		if (isEmpty(s)) return true;
	
		// Search through string's characters one by one
		// until we find a non-whitespace character.
		// When we do, return false; if we don't, return true.
	
		for (i = 0; i < s.length; i++)
		{   
			// Check that current character isn't whitespace.
			var c = s.charAt(i);
	
			if (whitespace.indexOf(c) == -1) return false;
		}
	
		// All characters are whitespace.
		return true;
	}
	function isEmpty(s){   	
		return ((s == null) || (s.length == 0))
	}
	function isEmail (s){   
		if (isEmpty(s)) 
		   if (isEmail.arguments.length == 1) return defaultEmptyOK;
		   else return (isEmail.arguments[1] == true);
	   
		// is s whitespace?
		if (isWhitespace(s)) return false;
		
		// there must be >= 1 character before @, so we
		// start looking at character position 1 
		// (i.e. second character)
		var i = 1;
		var sLength = s.length;
	
		// look for @
		while ((i < sLength) && (s.charAt(i) != "@"))
		{ i++
		}
	
		if ((i >= sLength) || (s.charAt(i) != "@")) return false;
		else i += 2;
	
		// look for .
		while ((i < sLength) && (s.charAt(i) != "."))
		{ i++
		}
	
		// there must be at least one character after the .
		if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
		else return true;
	}
	function comprobarCondiciones(){
		if (document.participa.nombre.value!=""){
			if (document.participa.apellidos.value!=""){
				if(document.participa.email.value!=""){
					if (isEmail(document.participa.email.value) == true ) { 
							if(document.participa.textarea.value!=""){
										document.participa.submit();
							}
							else{
								alert("El campo 'Mensaje' es obligatorio");
								document.participa.textarea.focus();
								return false;
							}
					}else{
						alert("El campo 'E-mail' debe contener un email. (Ej. email@dominio.com)");
					    document.participa.email.focus();  
				    	return(false);
					}
				}
				else{
					alert("El campo 'E-mail' es obligatorio");
					document.participa.email.focus();
					return false;
				}
			}
			else {
			alert("El campo 'Apellidos' es obligatorio");
			document.participa.apellidos.focus();
			return false;
		}
		}
		else {
			alert("El campo 'Nombre' es obligatorio");
			document.participa.nombre.focus(); 
			return false;
		}
	}