var yomotsuClearDefaultValue = {
	main : function(){
		var i;
		var input = document.getElementsByTagName("input");
		var textarea = document.getElementsByTagName("textarea");
		
		// input ---
		for (i=0;i<input.length;i++){
			if((input[i].getAttribute("type") == "text")||(input[i].getAttribute("type") == null)){
				if (input[i].value == input[i].defaultValue){
					input[i].className += " default-value"
				}
				input[i].onfocus = yomotsuClearDefaultValue.Focus;
				input[i].onblur  = yomotsuClearDefaultValue.Blur;
			}
		}
		
		// textarea ---
		for (i=0;i<textarea.length;i++){
			if (textarea[i].value == textarea[i].defaultValue){
				textarea[i].className += " default-value"
			}
			textarea[i].onfocus = yomotsuClearDefaultValue.Focus;
			textarea[i].onblur  = yomotsuClearDefaultValue.Blur;
		}
	},
	
	Focus : function(){
		if (this.value == this.defaultValue){
			this.value = "";
			this.className = this.className.replace(/default-value/, "");
		}
	},
	
	Blur : function(){
		if (this.value == ""){
			this.value = this.defaultValue;
			this.className += " default-value";
		}
	},
	
	addEvent : function(){
		try {
			window.addEventListener('load', yomotsuClearDefaultValue.main, false);
		} catch (e) {
			window.attachEvent('onload', yomotsuClearDefaultValue.main);
		}
	}
	
}

yomotsuClearDefaultValue.addEvent();