Clean whitespaces from IBAN when pasting it on BPINet

bpinet_clean_iban.js

//Add as many IBAN / NIB field IDs as you want
var ibanFields = [
    "LT_BPINet_wt1_block_wtMainContent_CS_ClienteCanais_wt42_block_WebPatterns_wt581_block_wtContent_LT_BPI_Patterns_wtDadosBeneficiarioNacional_block_wtForm_LT_BPI_Patterns_wtRowIBAN_block_wtRow_LT_BPI_Patterns_wtIBAN_block_wtInput_wtTxtIBAN",
    "LT_BPINet_wt20_block_wtMainContent_CS_Transferencias_wt12_block_wt3_WebPatterns_wt820_block_wtContent_LT_BPI_Patterns_wtfmFomularioDadosTranferencia_block_wtForm_LT_BPI_Patterns_wttxtIBAN_block_wtRow_LT_BPI_Patterns_wt652_block_wtInput_wttxtIBAN2",
    "LT_BPINet_wt60_block_wtMainContent_CS_Transferencias_wt68_block_WebPatterns_wt273_block_wtContent_LT_BPI_Patterns_wt999_block_wtForm_LT_BPI_Patterns_wt442_block_wtRow_LT_BPI_Patterns_wt55_block_wtInput_wttxtContaIBANDestinatario"
];

//Add the event listener
for (var i = 0, len = ibanFields.length; i < len; i++) {
    if ( el=document.getElementById(ibanFields[i]) ) el.addEventListener('paste', cleanIban);
}

//Clean it on paste!
function cleanIban(e) {
    e.stopPropagation();
    e.preventDefault();
    var clipboardData = e.clipboardData || window.clipboardData;
    var iban = clipboardData.getData('Text');
    iban = iban.replace(/\s/g,'');
    document.getElementById(this.id).value = iban;
}

This is quick and dirty. Can, and should, be improved.