currentInput=null;
function setFocusEvent(inp){
	inp.onfocus=function(){
		currentInput=this
	};
	inp.onblur=function(){
		currentInput=null}
};

var inputs=document.getElementsByTagName('input');
for(var i=0;i<inputs.length;i++)
if(inputs[i].type=='text'||inputs[i].type=='file')
	setFocusEvent(inputs[i]);
inputs=document.getElementsByTagName('textarea');

for(var i=0;i<inputs.length;i++)
	setFocusEvent(inputs[i]);

document.onkeydown=function(e){
	if(!currentInput){
		if(!e){
			e=window.event
		}
		if(e.ctrlKey){
			var code=e.keyCode?e.keyCode:(e.which?e.which:0);
			var arrow=code==37 ? document.getElementById('prev_page') : (code==39 ? document.getElementById('next_page'):0);
			if(arrow){
				location.href=arrow.href
			}
		}
	}
};