var mengvalue = -1;
if(mengvalue<0){mengvalue=0;}
var phoneWidth = parseInt(window.screen.width);
//物理分辨率
var phoneScale = phoneWidth / 750;
var ua = navigator.userAgent;
if (/Android (\d+\.\d+)/.test(ua)) {
	var version = parseFloat(RegExp.$1);
	// andriod 2.3
	if (version > 2.3) {
		document.write('<meta name="viewport" content="width=750, minimum-scale = ' + phoneScale + ', maximum-scale = ' + phoneScale + ', target-densitydpi=device-dpi">');
		// andriod 2.3以上 
	} else {
		document.write('<meta name="viewport" content="width=750, target-densitydpi=device-dpi">');
	}
//其他系统 
} else {
	document.write('<meta name="viewport" content="width=750, user-scalable=no, target-densitydpi=device-dpi">');
}