document.onload=init();

function init(){
	event_addListener(document, 'mousedown', dostuff);
}

function dostuff() {
	if(document.forms[0]){
		event_addListener(document.forms[0], 'click', blankit);
	}
}

function blankit() {
	var target = event.target || event.srcElement;
	if(target.tagName == 'INPUT' && target.type == 'text'){
		if(target.value.substring(0,1) == '-'){
			target.value = '';
		}
	}
	
}

function print_r(obj){
	var str = '';
	for(var prop in obj){
		str += prop + " value :" + obj[prop] + "\n";
	}
	alert(str);
}