var Validation = {
	
	select_List : function(id, msg) {
		var obj = document.getElementById(id).options[document.getElementById(id).selectedIndex];
		if (obj.value == '-1') {
			alert(msg);
			document.getElementById(id).focus();
			return false; 
		} else {
			return true;
		}		
	},

	logo : function(id, msg) {
		//checks for logo's either new or existing
		var newlogo = document.getElementById(id);
		var existinglogo = document.getElementById('img_' + id);
		if ((existinglogo.value != '') || (newlogo.value != '')) {
			return true;
		} else {
			alert(msg);
			document.getElementById(id).focus();
			return false;
		}
		
	},

	i : function(id, msg) {
		var obj = document.getElementById(id);
		var result = this.validate_by_regexp(obj, msg, '^-?\\d+$', obj);
		return result;
	},

	m : function(id, msg) {
		var obj = document.getElementById(id);
		var result = this.validate_by_regexp(obj, msg, '^-?\\d+(\\.?\\d+)?$', obj);
		return result;
	},

	s : function(id, msg) {
		//checks non empty string
		var obj = document.getElementById(id);
		var result = this.validate_by_regexp(obj, msg, '.+', obj);
		return result;
	},

	c : function(id, msg) {
		//checks for ticked checkboxes
		var result;
		var check = document.getElementById(id);
		if (check.checked == true) {
			result = true;
		} else {
			alert(msg);
			check.focus();
			result = false;
		}
		return result;
	},
	
	validate_by_regexp : function (obj, msg, regexp, objFocus) {
		if (obj.value.search(regexp) == -1) {
			alert(msg);
			objFocus.focus();
			return false; 
		} else {
			return true;
		}
	}

}