function isIE() {
	return /msie/i.test(navigator.userAgent) && !/opera/i.test(navigator.userAgent);
}
function grayscale(imgObj)
{
	imgObj=document.getElementById(imgObj);
	if(isIE()) {
		grayscaleImageIE(imgObj);
	}
	else {
		imgObj.src = grayscaleImage(imgObj);
	}
}
function grayscaleImageIE(imgObj)
{
    imgObj.style.filter = 'progid:DXImageTransform.Microsoft.BasicImage(grayScale=1)';
}
function grayscaleImage(imgObj)
{
    var canvas = document.createElement('canvas');
    var canvasContext = canvas.getContext('2d');

    var imgW = imgObj.width;
    var imgH = imgObj.height;
    canvas.width = imgW;
    canvas.height = imgH;

    canvasContext.drawImage(imgObj, 0, 0);
    var imgPixels = canvasContext.getImageData(0, 0, imgW, imgH);

    for(var y = 0; y < imgPixels.height; y++){
        for(var x = 0; x < imgPixels.width; x++){
            var i = (y * 4) * imgPixels.width + x * 4;
            var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2]) / 3;
            imgPixels.data[i] = avg;
            imgPixels.data[i + 1] = avg;
            imgPixels.data[i + 2] = avg;
        }
    }

    canvasContext.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
    return canvas.toDataURL();
}
function checknum(that){
	if(that.value=="")
	{
		that.value="0";
	}
	else
	{
		t=parseFloat(that.value);
		if (isNaN(t))
		{
			alert("В данное поле можно вводить только цифры!");
			that.value="0";
		}
		else
		{
			if(t<0)
			{
				t=t+(t*2*-1);
			};
			that.value=t;
		}
	}
}

function openbig(path,width,height,wnd)
{
	window.open(path,wnd,"toolbar=no,location=no,directories=no,status=no,menubar=no,resize=no,scrollbars=yes,width="+width+",height="+height);
}

function textCounter(field, maxlimit) {
	if (field.value.length > maxlimit)
	{
		field.value = field.value.substring(0, maxlimit);
		alert("В данном поле не может быть более "+maxlimit+" символов.");
	}
}

function checkMultis(field, input, text, textout) {
	text+="<br>";
	textout+="<br>";
	if(document.getElementById(field).innerHTML=='&nbsp;')
	{
		document.getElementById(field).innerHTML='';
	}
	if(document.getElementById(input).checked)
	{
		document.getElementById(field).innerHTML+=text;
	}
	else
	{
		var re = new RegExp(textout, 'i');
		document.getElementById(field).innerHTML=document.getElementById(field).innerHTML.replace(re,'');
	}
	if(document.getElementById(field).innerHTML=='')
	{
		document.getElementById(field).innerHTML='&nbsp;';
	}
}

function checkMultisOne(field, input, text) {
	if(document.getElementById(field).innerHTML=='&nbsp;')
	{
		document.getElementById(field).innerHTML='';
	}
	if(document.getElementById(input).checked)
	{
		document.getElementById(field).innerHTML=text;
	}
	if(document.getElementById(field).innerHTML=='')
	{
		document.getElementById(field).innerHTML='&nbsp;';
	}
}