function trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}
function select_field(el, blank_str){
	if(el.value==blank_str){
		el.value='';	
	}else{
		el.select();
	}
}
function check_clear_field(el, blank_str){
	if(trim(el.value)==""){
		el.value=blank_str;	
	}
}