jQuery.fn.input_text_explain = function(txt, color_explain, color_normal) {
	var xgri = (color_explain ? color_explain : '#aaaaaa');
	var xnegru = (color_normal ? color_normal : '#000000');
	function focus_blur_log_user(obe,_focus)
	{
		var txtdef = txt;
		if(_focus){		
			if(obe.value.replace(/[\r\n'`]/gi,'')==txtdef.replace(/[\r\n'`]/gi,'')){ 
				obe.value='';		
				obe.style.color = xnegru;
			}
		}else{
			if(obe.value==''){ 
				obe.value=txtdef;
				obe.style.color = xgri;
			}
		}
	}

  return this.each(function(){  	
  	if(typeof txt == 'undefined' || txt=='') return;
    this.onblur  = function(){ focus_blur_log_user(this,false); }
    this.onfocus = function(){ focus_blur_log_user(this,true); }
    if(this.value == ''){
		this.value = txt;
		this.style.color = xgri;
	} 
  });
  
};