/*==========================================================================# 
# * Function for adding a Filter to an Input Field                          # 
# * @param  : [filterType  ] Type of filter 0=>Alpha, 1=>Num, 2=>AlphaNum   # 
# * @param  : [evt         ] The Event Object                               # 
# * @param  : [allowDecimal] To allow Decimal Point set this to true        # 
# * @param  : [allowCustom ] Custom Characters that are to be allowed       # 
#==========================================================================*/
function filterInput(filterType, evt, allowDecimal, allowCustom) {
    var keyCode, Char, inputField, filter = '';
    var alpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    var num = '0123456789';
    // Get the Key Code of the Key pressed if possible else - allow 
    if (window.event) {
        keyCode = window.event.keyCode;
        evt = window.event;
    } else if (evt) keyCode = evt.which;
    else return true;
    // Setup the allowed Character Set 
    if (filterType == 0) filter = alpha;
    else if (filterType == 1) filter = num;
    else if (filterType == 2) filter = alpha + num;
    if (allowCustom) filter += allowCustom;
    if (filter == '') return true;
    // Get the Element that triggered the Event 
    inputField = evt.srcElement ? evt.srcElement : evt.target || evt.currentTarget;
    // If the Key Pressed is a CTRL key like Esc, Enter etc - allow 
    if ((keyCode == null) || (keyCode == 0) || (keyCode == 8) || (keyCode == 9) || (keyCode == 13) || (keyCode == 27)) return true;
    // Get the Pressed Character 
    Char = String.fromCharCode(keyCode);
    // If the Character is a number - allow 
    if ((filter.indexOf(Char) > -1)) return true;
    // Else if Decimal Point is allowed and the Character is '.' - allow 
    else if (filterType == 1 && allowDecimal && (Char == '.') && inputField.value.indexOf('.') == -1) return true;
    else return false;
}

/*==========================================================================# 
# * Function for adding a Filter to an Input Field                          # 
# * @param  : [filterType  ] Type of filter 0=>Alpha, 1=>Num, 2=>AlphaNum   # 
# * @param  : [evt         ] The Event Object                               # 
# * @param  : [allowDecimal] To allow Decimal Point set this to true        # 
# * @param  : [allowCustom ] Custom Characters that are to be allowed       # 
# * @param  : [replaceChars] Chars which should be replaced                 #
# * @param  : [replacementChars] Chars which replace replaceChars           #
#==========================================================================*/
function filterInput(filterType, evt, allowDecimal, allowCustom, replaceChars, replacementChars) {
    var keyCode, Char, inputField, filter = '';
    var alpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    var num = '0123456789';
    // Get the Key Code of the Key pressed if possible else - allow 
    if (window.event) {
        keyCode = window.event.keyCode;
        evt = window.event;
    } else if (evt) keyCode = evt.which;
    else return true;
    // Setup the allowed Character Set 
    if (filterType == 0) filter = alpha;
    else if (filterType == 1) filter = num;
    else if (filterType == 2) filter = alpha + num;
    if (allowCustom) filter += allowCustom;
    if (filter == '') return true;
    // Get the Element that triggered the Event 
    inputField = evt.srcElement ? evt.srcElement : evt.target || evt.currentTarget;
    // If the Key Pressed is a CTRL key like Esc, Enter etc - allow 
    if ((keyCode == null) || (keyCode == 0) || (keyCode == 8) || (keyCode == 9) || (keyCode == 13) || (keyCode == 27)) return true;
    // Get the Pressed Character
    Char = String.fromCharCode(keyCode);
    // If pressed key is part of replaceChars - replace
    if (replaceChars.indexOf(Char) > -1) {
        if (window.event)
            keyCode = window.event.keyCode = replacementChars.charCodeAt(replaceChars.indexOf(Char));
        else if (evt)
            keyCode = evt.which = replacementChars.charCodeAt(replaceChars.indexOf(Char));
        Char = String.fromCharCode(keyCode);
    }
    // If the Character is a number - allow 
    if ((filter.indexOf(Char) > -1)) return true;
    // Else if Decimal Point is allowed and the Character is '.' - allow 
    else if (filterType == 1 && allowDecimal && (Char == '.') && inputField.value.indexOf('.') == -1) return true;
    else return false;
}