function onPostBack() {
    var y = generateRandomSequence();
    var hdnGuid = document.getElementById("hdnGuid");
    hdnGuid.value = y;
}

function generateRandomSequence() {
    var g = "";
    for (var i = 0; i < 32; i++)
        g += Math.floor(Math.random() * 0xF).toString(0xF)
    return g;
}

function HideLabel(txtField) {
    if (txtField.name == 'ctl00$MainContent$ucSearch$txtSearch') {
        if (txtField.value == 'Enter search string')
            txtField.value = '';
        else
            txtField.select();
    } else if (txtField.name == 'ctl00$txtPassword') {
        if (txtField.value == 'Password') {
            txtField.value = '';
            txtField.type = 'Password';
        }
        else {
            txtField.type = 'password';
            txtField.select();
        }
    } else if (txtField.name == 'ctl00$MainContent$txtProductName') {
        if (txtField.value == 'Enter product name')
            txtField.value = '';
        else
            txtField.select();
    } else if (txtField.name == 'ctl00$MainContent$txtCAS') {
        if (txtField.value == 'Enter CAS number')
            txtField.value = '';
        else
            txtField.select();
    } else if (txtField.name == 'ctl00$MainContent$txtCat') {
        if (txtField.value == 'Enter Category')
            txtField.value = '';
        else
            txtField.select();
    } else if (txtField.name == 'ctl00$txtUser') {
        if (txtField.value == 'User Name')
            txtField.value = '';
        else
            txtField.select();
    }
}

function ShowLabel(txtField) {
    
    if (txtField.name == 'ctl00$MainContent$ucSearch$txtSearch') {
        if (txtField.value.trim() == '')
            txtField.value = 'Enter search string';
    } else if (txtField.name == 'ctl00$txtPassword') {
        if (txtField.value.trim() == '') {
            txtField.value = 'Password';
            txtField.type = 'text';
        }
    } else if (txtField.name == 'ctl00$MainContent$txtProductName') {
        if (txtField.value.trim() == '')
            txtField.value = 'Enter product name';
    } else if (txtField.name == 'ctl00$MainContent$txtCAS') {
        if (txtField.value.trim() == '')
            txtField.value = 'Enter CAS number';
    } else if (txtField.name == 'ctl00$MainContent$txtCat') {
        if (txtField.value.trim() == '')
            txtField.value = 'Enter Category';
    } else if (txtField.name == 'ctl00$txtUser') {
        if (txtField.value.trim() == '')
            txtField.value = 'User Name';
    }
}