function checkFile(obj) {
var fileElement = document.getElementById(obj);
var fileExtension = "";
if (fileElement.value.lastIndexOf(".") > 0) {
fileExtension = fileElement.value.substring(fileElement.value.lastIndexOf(".") + 1, fileElement.value.length);
}
if (fileExtension == "gif" || fileExtension == "GIF" || fileExtension == "JPEG" || fileExtension == "jpeg" || fileExtension == "jpg" || fileExtension == "JPG" || fileExtension == "PNG" || fileExtension == "png") {
return true;
}
else {
alert("You must select a GIF,JPEG,JPG and PNG file for upload");
document.getElementById(obj).value = '';
fileElement.focus();
return false;
}
}
try this it is some what useful for u?
Before Posting Question provide some clear picture about your faced problem.